POLAR TANKERS, INC. v. CITY OF VALDEZ, ALASKA

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CASES ADJUDGED
IN THE
SUPREME COURT OF THE UNITED STATES
AT
OCTOBER TERM, 2008
POLAR TANKERS, INC. v. CITY OF VALDEZ, ALASKA
certiorari to the supreme court of alaska
No. 08–310. Argued April 1, 2009—Decided June 15, 2009
A Valdez, Alaska, ordinance that imposes a personal property tax on cer
tain boats and vessels contains exceptions which, in effect, largely limit
its applicability to large oil tankers. Petitioner Polar Tankers, Inc.,
whose vessels transport crude oil from the Port of Valdez to refineries
in other States, challenged the ordinance in state court, claiming (1) that
the tax was unconstitutional under Art. I, § 10, cl. 3, which forbids
a “State . . . without the Consent of Congress, [to] lay any Duty of
Tonnage,” and (2) that the tax’s value-allocation method violated the
Commerce and Due Process Clauses. The court rejected the Tonnage
Clause claim, but accepted the Commerce Clause and Due Process
Clause claim. On appeal, the State Supreme Court upheld the tax,
finding that because it was a value-based property tax, the tax was
not a duty of tonnage. The State Supreme Court also held the alloca
tion method was fair and thus valid under the Commerce and Due Proc
ess Clauses.
Held: The judgment is reversed, and the case is remanded.
182 P. 3d 614, reversed and remanded.
Justice Breyer delivered the opinion of the Court with respect
to Parts I, II–A, and II–B–1, concluding that Valdez’s tax violates the
Tonnage Clause. Consequently, Polar Tankers’ alternative Commerce
Clause and Due Process Clause arguments need not be considered.
Pp. 6–11.
1

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2 POLAR TANKERS, INC. v. CITY OF VALDEZ
Syllabus
(a) This Court has consistently interpreted the language of the Ton
nage Clause in light of its purpose, which mirrors the intent of other
constitutional provisions that seek to restrain the States from exercising
the taxing power in a way that is injurious to the interests of other
States. The Clause seeks to prevent States from nullifying Art. I, § 10,
cl. 2’s prohibition against import and export duties by taxing “the ves
sels transporting the merchandise.” Clyde Mallory Lines v. Alabama
ex rel. State Docks Comm’n, 296 U. S. 261, 265. It also reflects an effort
to diminish a State’s ability to obtain tax advantages based on its favor
able geographic position. Because the Clause forbids a State to “do
that indirectly which she is forbidden . . . to do directly,” Passenger
Cases, 7 How. 283, 458, the “prohibition against tonnage duties has been
deemed to embrace all taxes and duties regardless of their name or
form, and even though not measured by the tonnage of the vessel, which
operate to impose a charge for the privilege of entering, trading in, or
lying in a port,” Clyde Mallory Lines, supra, at 265–266. Pp. 6–9.
(b) This case lies at the heart of what the Tonnage Clause forbids.
The ordinance seems designed to impose “a charge for the privilege of
entering, trading in, or lying in a port.” The tax applies almost exclu
sively to oil tankers, but to no other form of personal property. An oil
tanker can be subject to the tax based on a single entry into the port.
Moreover, the tax is closely correlated with cargo capacity. Contrary
to Valdez’s argument, the fact that the tax is designed to raise revenue
for general municipal services argues for, not against, application of the
Clause. Pp. 9–11.
Justice Breyer, joined by Justice Scalia, Justice Kennedy, and
Justice Ginsburg, rejected, in Part II–B–2, Valdez’s claim that, under
State Tonnage Tax Cases, 12 Wall. 204, its tax is “not within the prohibi
tion of the Constitution,” because it is “levied . . . upon ships . . . as
property, based on a valuation of the same as property,” id., at 213 (em
phasis deleted). This Court later made clear that the “prohibition”
against tonnage duties “comes into play” where vessels “are not taxed
in the same manner as the other property of the citizens,” Transporta
tion Co. v. Wheeling, 99 U. S. 273, 284. This qualification, important in
light of the Clause’s purpose, means that, in order to fund services by
taxing ships, a State must also impose similar taxes upon other busi
nesses. Valdez fails to satisfy this requirement. The Court can find
little, if any, other personal property that Valdez taxes. Because its
value-related property tax on mobile homes, trailers, and recreational
vehicles applies only if they are “affixed” to a particular site, it taxes
those vehicles as a form of real, not personal, property. Valdez also
claims that its ship tax is simply another form of a value-based tax on

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3 Cite as: 557 U. S. 1 (2009)
Syllabus
oil-related property provided by state law. But Valdez’s tax, a purely
municipal tax, differs from the tax on other oil-related property, which
is primarily a state-level tax, in several ways. As a result of these
differences, an ordinary oil-related business finding the tax on its mov
able property too burdensome must complain to the State, which is in
charge of setting the manner of assessment and valuation. At the same
time, an oil tanker finding its vessel tax too burdensome must complain
to Valdez, for the State has nothing to do with that tax’s rate, valuation,
or assessment. There is also no effective electorate-related check on
Valdez’s vessel-taxing power comparable to the check available when a
property tax is more broadly imposed. Valdez’s property tax hits only
ships; it is not constrained by any need to treat ships and other business
property alike. Thus, Valdez’s tax lacks the safeguards implied by this
Court’s statements that a property tax on ships escapes the Tonnage
Clause’s scope only when that tax is imposed upon ships “in the same
manner” as it is imposed on other forms of property. Pp. 11–16.
The Chief Justice, joined by Justice Thomas, agreed that Valdez’s
tax is unconstitutional, but concluded that the city’s argument that its
tax may be sustained as a property tax similar to ones the city imposes
on other property should be rejected because an unconstitutional tax
on maritime commerce does not become permissible when bundled with
taxes on other activities or property. Pp. 17–19.
Justice Alito agreed that Valdez’s tax is unconstitutional, but con
cluded that the tax is an unconstitutional duty of tonnage even if the
Tonnage Clause permits a true, evenhanded property tax to be applied
to vessels. Pp. 19–20.
Breyer, J., announced the judgment of the Court and delivered the
opinion of the Court with respect to Parts I, II–A, and II–B–1, in which
Scalia, Kennedy, Ginsburg, and Alito, JJ., joined, and an opinion with
respect to Part II–B–2, in which Scalia, Kennedy, and Ginsburg, JJ.,
joined. Roberts, C. J., filed an opinion concurring in part and concurring
in the judgment, in which Thomas, J., joined, post, p. 17. Alito, J., filed
an opinion concurring in part and concurring in the judgment, post, p. 19.
Stevens, J., filed a dissenting opinion, in which Souter, J., joined, post,
p. 20.
Charles A. Rothfeld argued the cause for petitioner.
With him on the briefs were Andrew L. Frey and Richard
A. Leavy.

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4 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of the Court
Theodore B. Olson argued the cause for respondent.
With him on the brief were Matthew D. McGill, Amir C.
Tayrani, William M. Walker, and Debra J. Fitzgerald.*
Justice Breyer announced the judgment of the Court
and delivered the opinion of the Court with respect to
Parts I, II–A, and II–B–1, and an opinion with respect to
Part II–B–2, in which Justice Scalia, Justice Kennedy,
and Justice Ginsburg join.
The Constitution forbids a “State . . . without the Consent
of Congress, [to] lay any Duty of Tonnage.” Art. I, § 10, cl. 3.
The city of Valdez, Alaska, has enacted an ordinance that
imposes a personal property tax upon the value of large
ships that travel to and from that city. We hold that the
ordinance violates the Clause.
*Briefs of amici curiae urging reversal were filed for the Council on
State Taxation by Todd A. Lard, Douglas L. Lindholm, and Frederick J.
Nicely; for the National Federation of Independent Business Small Busi
ness Legal Center by Karen R. Harned and Elizabeth Milito; and for the
Tropical Shipping and Construction Co., Ltd., by Jonathan F. Mitchell
and Paul C. Gracey, Jr.
Briefs of amici curiae urging affirmance were filed for the State of
Alaska et al. by Richard Svobodny, Acting Attorney General of Alaska,
Craig J. Tillery, Deputy Attorney General, Joanne M. Grace, Assistant
Attorney General, David C. Frederick, and Scott H. Angstreich, by Rich
ard S. Gebelein, Chief Deputy Attorney General of Delaware, and by the
Attorneys General for their respective States as follows: Troy King of
Alabama, Dustin McDaniel of Arkansas, John W. Suthers of Colorado,
Bill McCollum of Florida, Lawrence G. Wasden of Idaho, Douglas F.
Gansler of Maryland, Martha Coakley of Massachusetts, Steve Bullock of
Montana, Anne Milgram of New Jersey, Roy Cooper of North Carolina,
Richard Cordray of Ohio, Mark L. Shurtleff of Utah, Robert M. McKenna
of Washington, Darrell V. McGraw, Jr., of West Virginia, and Bruce A.
Salzburg of Wyoming; and for the Multistate Tax Commission by Joe B.
Huddleston and Shirley K. Sicilian.
Briefs of amici curiae were filed for the Broadband Tax Institute by
Jerome B. Libin, Jeffrey A. Friedman, and Marc A. Simonetti; and for
the World Shipping Council et al. by Marc J. Fink, John W. Butler, Law
rence W. Kaye, and Andre´ M. Picciurro.

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Cite as: 557 U. S. 1 (2009) 5
In 1999, the
Opinion of the Court
I
city of Valdez, Alaska (City or Valdez),
adopted an ordinance imposing a personal property tax upon
“[b]oats and vessels of at least 95 feet in length” that regu
larly travel to the City, are kept or used within the City, or
which annually take on at least $1 million worth of cargo or
engage in other business transactions of comparable value
in the City. Valdez Ordinance No. 99–17 (1999) (codified as
Valdez Municipal Code § 3.12.020 (2008)). The ordinance
contains exceptions that, in effect, limit the tax’s applicabil
ity primarily to large oil tankers. Ibid. And the City ap
plies the tax in accordance with a value-allocation system
that adjusts the amount owed downwards insofar as the
tankers spend time in other ports. Valdez, Alaska, Resolu
tion No. 00–15, App. to Pet. for Cert. 53a–56a.
Polar Tankers, Inc., a subsidiary of ConocoPhillips, owns
vessels that transport crude oil from a terminal in the Port
of Valdez (located at the southern end of the Trans Alaska
Pipeline System) to refineries in California, Hawaii, and
Washington. In August 2000, Polar Tankers filed a lawsuit
in Alaska Superior Court challenging the tax as unconstitu
tional. Polar Tankers argued that the tax effectively im
posed a fee on certain vessels for the privilege of entering
the port; hence it amounted to a constitutionally forbidden
“Duty of Tonnage.” It also argued that the tax calculation
method (as applied to vessels with a tax situs elsewhere)
violated the Commerce and Due Process Clauses by fail
ing to take account of the time a ship spent at sea or being
serviced or repaired. Polar Tankers said that the method
thereby overstated the percentage of the ship’s total earning
capacity reasonably allocated to time spent in the Port of
Valdez.
The Alaska Superior Court rejected the Tonnage Clause
claim, but it accepted the Commerce Clause and Due Process
Clause claim. And, for that reason, it held the tax unconsti
tutional. On appeal, the Alaska Supreme Court, rejecting

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6 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of the Court
both claims, upheld the tax. In respect to the Tonnage
Clause claim, the Supreme Court noted that Valdez’s tax was
a value-based property tax designed to pay for “services
available to all taxpayers in the city,” including Polar Tank
ers; and it concluded that “a charge based on the value of
property is not a duty of tonnage.” 182 P. 3d 614, 623 (2008)
(citing Transportation Co. v. Wheeling, 99 U. S. 273 (1879)).
In respect to the Commerce Clause and Due Process Clause
claim, the Supreme Court held that Valdez’s allocation
method was fair, hence constitutional. 182 P. 3d, at 617–622.
Polar Tankers asked us to review the Alaska Supreme
Court’s determination. And we granted its petition in order
to do so.
II
A
We begin, and end, with Polar Tankers’ Tonnage Clause
claim. We hold that Valdez’s tax is unconstitutional because
it violates that Clause. And we consequently need not con
sider Polar Tankers’ alternative Commerce Clause and Due
Process Clause argument.
When the Framers originally wrote the Tonnage Clause,
the words it uses, “Duty of Tonnage,” referred in commercial
parlance to “a duty” imposed upon a ship, which duty varies
according to “the internal cubic capacity of a vessel,” i. e., its
tons of carrying capacity. Clyde Mallory Lines v. Alabama
ex rel. State Docks Comm’n, 296 U. S. 261, 265 (1935) (citing
Inman S. S. Co. v. Tinker, 94 U. S. 238, 243 (1877)); see also
T. Cooley, Constitutional Limitations 596 (6th ed. 1890).
Over a century ago, however, this Court found that the
Framers intended those words to refer to more than “a duty”
that sets a “certain rate on each ton” of capacity. Steamship
Co. v. Portwardens, 6 Wall. 31, 34 (1867).
The Court over the course of many years has consistently
interpreted the language of the Clause in light of its purpose,
a purpose that mirrors the intent of other constitutional pro

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7 Cite as: 557 U. S. 1 (2009)
Opinion of the Court
visions which, like the Tonnage Clause itself, seek to “re
strai[n] the states themselves from the exercise” of the tax
ing power “injuriously to the interests of each other.” J.
Story, Commentaries on the Constitution of the United
States § 497, p. 354 (1833) (abridged version). Article I, § 10,
cl. 2, for example, forbids States to “lay any Imposts or Du
ties on Imports or Exports.” It thereby seeks to prevent
States with “convenient ports” from placing other States at
an economic disadvantage by laying levies that would “ta[x]
the consumption of their neighbours.” 3 Records of the
Federal Convention of 1787, pp. 542, 519 (M. Farrand ed.
1966) (reprinting James Madison, Preface to Debates in the
Convention of 1787 and letter from James Madison to Profes
sor Davis, 1832). The coastal States were not to “take ad
vantage of their favorable geographical position in order to
exact a price for the use of their ports from the consumers
dwelling in less advantageously situated parts of the coun
try.” Youngstown Sheet & Tube Co. v. Bowers, 358 U. S.
534, 556–557 (1959) (Frankfurter, J., dissenting in part).
In writing the Tonnage Clause, the Framers recognized
that, if “the states had been left free to tax the privilege of
access by vessels to their harbors the prohibition against du
ties on imports and exports could have been nullified by tax
ing the vessels transporting the merchandise.” Clyde Mal
lory Lines, supra, at 265. And the Court has understood
the Tonnage Clause as seeking to prevent that nullification.
See Steamship Co., supra, at 34–35; see also Packet Co. v.
Keokuk, 95 U. S. 80, 87 (1877); Gibbons v. Ogden, 9 Wheat. 1,
202 (1824). It has also understood the Clause as reflecting
an effort to diminish a State’s ability to obtain certain geo
graphical vessel-related tax advantages whether the vessel
in question transports goods between States and foreign na
tions or, as here, only between the States. Compare Inman,
supra (invalidating a fee applied to ships engaged in foreign
commerce), with Steamship Co., supra (invalidating a tax
applied to ships engaged in interstate commerce).

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8 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of the Court
Interpreting the Clause in light of its “intent,” id., at 34,
we have read its language as forbidding a State to “do that
indirectly which she is forbidden . . . to do directly,” Pas
senger Cases, 7 How. 283, 458 (1849) (opinion of Grier, J.).
Thus, we have said that the Clause, which literally forbids a
State to “levy a duty or tax . . . graduated on the tonnage,”
must also forbid a State to “effect the same purpose by
merely changing the ratio, and graduating it on the number
of masts, or of mariners, the size and power of the steam
engine, or the number of passengers which she carries.”
Id., at 458–459. A State cannot take what would otherwise
amount to a tax on the ship’s capacity and evade the Clause
by calling that tax “a charge on the owner or supercargo,”
thereby “justify[ing] this evasion of a great principle by pro
ducing a dictionary or a dictum to prove that a ship-captain
is not a vessel, nor a supercargo an import.” Id., at 459.
The Court has consequently stated that the Tonnage
Clause prohibits, “not only a pro rata tax . . . , but any duty
on the ship, whether a fixed sum upon its whole tonnage, or
a sum to be ascertained by comparing the amount of tonnage
with the rate of duty.” Steamship Co., supra, at 35. And,
summarizing earlier cases while speaking for a unanimous
Court, Justice Stone concluded that the “prohibition against
tonnage duties has been deemed to embrace all taxes and
duties regardless of their name or form, and even though not
measured by the tonnage of the vessel, which operate to im
pose a charge for the privilege of entering, trading in, or
lying in a port.” Clyde Mallory Lines, supra, at 265–266.
Cf. Cannon v. New Orleans, 20 Wall. 577 (1874) (invalidating
a tax imposed on ships entering a port, which tax was gradu
ated based on the ships’ capacity and length of stay); Inman,
supra (invalidating a fee imposed on ships of a certain capac
ity that entered a port); Steamship Co., supra (invalidating
a flat tax imposed on every ship that entered a port, regard
less of the ship’s capacity).

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9 Cite as: 557 U. S. 1 (2009)
Opinion of the Court
Although the Clause forbids all charges, whatever their
form, that impose “a charge for the privilege of entering,
trading in, or lying in a port,” nothing in the history of the
adoption of the Clause, the purpose of the Clause, or this
Court’s interpretation of the Clause suggests that it operates
as a ban on any and all taxes which fall on vessels that use
a State’s port, harbor, or other waterways. See post, at 17
(Roberts, C. J., concurring in part and concurring in judg
ment). Such a radical proposition would transform the Ton
nage Clause from one that protects vessels, and their owners,
from discrimination by seaboard States, to one that gives
vessels preferential treatment vis-a` -vis all other property,
and its owners, in a seaboard State. The Tonnage Clause
cannot be read to give vessels such “preferential treatment.”
Cf. Michelin Tire Corp. v. Wages, 423 U. S. 276, 287 (1976)
(noting, in a related context, that the Import-Export Clause
“cannot be read to accord imported goods preferential treat
ment that permits escape from uniform taxes imposed with
out regard to foreign origin for services which the State sup
plies”). See also infra this page and 10–16.
B
1
Does the tax before us impose “a charge for the privilege
of entering, trading in, or lying in a port”? Certainly, the
ordinance that imposes the tax would seem designed to do
so. It says that the tax applies to ships that travel to (and
leave) the City’s port regularly for business purposes, that
are kept in the City’s port, that take on more than $1 million
in cargo in that port, or that are involved in business trans
actions in that amount there. In practice, the tax applied
in its first year to 28 vessels, of which 24 were oil tankers,
3 were tugboats, and 1 was a passenger cruise ship. App.
53. The ordinance applies the tax to no other form of per
sonal property. See Valdez Municipal Code § 3.12.030(A)(2)
(2008).

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10 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of the Court
Moreover, the tax’s application and its amount depend
upon the ship’s capacity. That is to say, the tax applies only
to large ships (those at least 95 feet in length), while exempt
ing small ones. See § 3.12.020(A)(1).
Nor can Valdez escape application of the Clause by claim
ing that the ordinance imposes, not a duty or a tax, but a
fee or a charge for “services rendered” to a “vessel,” such
as “pilotage,” “wharfage,” “medical inspection,” the “use
of locks,” or the like. Clyde Mallory Lines, 296 U. S., at
266; see also Inman, 94 U. S., at 243. To the contrary, the
ordinance creates a tax designed to raise revenue used for
general municipal services. See 182 P. 3d, at 623; Valdez,
Alaska, Resolution No. 00–15, App. to Pet. for Cert. 53a–56a.
Tonnage Clause precedent makes clear that, where a tax oth
erwise qualifies as a duty of tonnage, a general, revenue
raising purpose argues in favor of, not against, application of
the Clause. See Steamship Co., 6 Wall., at 34.
This case lies at the heart of what the Tonnage Clause
forbids. The ordinance applies almost exclusively to oil
tankers. And a tax on the value of such vessels is closely
correlated with cargo capacity. Because the imposition of
the tax depends on a factor related to tonnage and that
tonnage-based tax is not for services provided to the vessel,
it is unconstitutional.
The dissent contends that the tax does not operate as
“a charge for the privilege of entering, trading in, or lying
in a port,” Clyde Mallory Lines, supra, at 265–266—that is,
as an impermissible tonnage duty—because Valdez levies its
tax only upon vessels that meet a “tax situs” requirement.
See post, at 24–25 (opinion of Stevens, J.). But in this case,
the distinction the dissent draws between tonnage duties and
property taxes is a distinction without a difference. That is
because to establish a tax situs under the tax challenged
here, an oil tanker needs only to enter the port and load oil
worth more than $1 million. And, as Polar Tankers notes,
oil tankers routinely carry millions of barrels of oil at a time

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11 Cite as: 557 U. S. 1 (2009)
Opinion of Breyer, J.
worth well in excess of $1 million. Reply Brief for Peti
tioner 6. Thus, by virtue of a single entry into the port,
“trading” once in that port, or “lying” once in that port, a
tanker automatically establishes a tax situs in Valdez. No
one claims that this basis for establishing a tax situs is insuf
ficient under the Constitution. After all, a nondomiciliary
jurisdiction may constitutionally tax property when that
property has a “substantial nexus” with that jurisdiction,
and such a nexus is established when the taxpayer “avails
itself of the substantial privilege of carrying on business” in
that jurisdiction. Mobil Oil Corp. v. Commissioner of
Taxes of Vt., 445 U. S. 425, 443, 437 (1980) (internal quotation
marks omitted). See also Japan Line, Ltd. v. County of Los
Angeles, 441 U. S. 434, 441–445 (1979); Quill Corp. v. North
Dakota, 504 U. S. 298, 312 (1992). Here, the City identified
the 28 vessels that were subject to the tax in the year 2000.
But the City fails to point to a single oil tanker, or any vessel
greater than 95 feet in length, that both entered the port
and failed to establish a tax situs. See App. 53. What else
is needed to show that a tax characterized as one on property
may nevertheless function as a “charge for the privilege of
entering . . . a port”?
2
Valdez does not deny that its tax operates much like a duty
applied exclusively to ships. But, like the Alaska Supreme
Court, it points to language in an earlier Court opinion ex
plicitly stating that “[t]axes levied . . . upon ships . . . as
property, based on a valuation of the same as property, are
not within the prohibition of the Constitution.” State Ton
nage Tax Cases, 12 Wall. 204, 213 (1871) (emphasis deleted);
cf. 182 P. 3d, at 622, and n. 43. Valdez says that its tax is
just such a value-related tax on personal property and conse
quently falls outside the scope of the Clause. Brief for Re
spondent 16–23.
Our problem with this argument, however, is that the
Court later made clear that the Clause does not apply to

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12 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of Breyer, J.
“taxation” of vessels “as property in the same manner
as other personal property owned by citizens of the State.”
“[W]here” vessels “are not taxed in the same manner as
the other property of the citizens,” however, the “prohibition
. . . comes into play.” Wheeling, 99 U. S., at 284 (emphasis
added).
Viewed in terms of the purpose of the Clause, this qualifi
cation is important. It means that, in order to fund services
by taxing ships, a State must also impose similar taxes upon
other businesses. And that fact may well operate as a check
upon a State’s ability to impose a tax on ships at rates that
reflect an effort to take economic advantage of the port’s
geographically based position. After all, the presence of
other businesses subject to the tax, particularly businesses
owned and operated by state residents, threatens political
concern and a potential ballot-box issue, were rates, say, to
get out of hand. See Cooley v. Board of Wardens of Port of
Philadelphia ex rel. Soc. for Relief of Distressed Pilots, 12
How. 299, 315 (1852); cf. South Carolina Highway Dept. v.
Barnwell Brothers, Inc., 303 U. S. 177, 185, n. 2 (1938) (when
state action affecting interstate commerce “is of such a char
acter that its burden falls principally upon those without the
state, legislative action is not likely to be subjected to those
political restraints which are normally exerted on legislation
where it affects adversely some interests within the state”).
Moreover, and at the very least, a “same manner” require
ment helps to ensure that a value-related property tax dif
fers significantly from a graduated tax on a ship’s capacity
and that the former is not simply a redesignation of the lat
ter. See Packet Co., 95 U. S., at 88 (“ ‘It is the thing and not
the name that is to be considered’ ” (quoting Cooley, supra,
at 314)).
In our view, Valdez fails to satisfy this requirement. It
does not tax vessels “in the same manner as other personal
property” of those who do business in Valdez. Wheeling,

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13 Cite as: 557 U. S. 1 (2009)
Opinion of Breyer, J.
supra, at 284. We can find little, if any, other personal prop
erty that it taxes. According to the State of Alaska, Valdez
specifically exempts from property taxation motor vehicles,
aircraft, and other vehicles, as well as business machinery.
See Dept. of Community and Economic Development, Divi
sion of Community and Business Development, Office of
the State Assessor, Alaska Taxable 2001, p. 20 (Jan. 2002)
(Table 4), online at http://www.commerce.state.ak.us/dca /
Taxable/AKTaxable2001.pdf (as visited June 10, 2009, and
available in Clerk of Court’s case file).
We concede, as Valdez points out, that a different Valdez
ordinance imposes what it characterizes as a value-based
property tax on mobile homes, trailers, and recreational ve
hicles. Valdez Municipal Code § 3.12.022 (2008); Brief for
Respondent 24–25. But that same ordinance exempts those
vehicles from its property tax unless they are “affixed” to
a particular site. Hence, whatever words the City uses to
describe the tax imposed on mobile homes, trailers, and rec
reational vehicles, Valdez in fact taxes those vehicles only
when they constitute a form, not of personal property, but of
real property (like a home). See § 3.12.022 (providing that
“trailers and mobile homes” are “subject to taxation” when
they are classified as “real property”).
Valdez also points to a separate city ordinance that im
poses a tax “on all taxable property taxable under Alaska
Statutes Chapter 43.56.” § 3.28.010 (2008). The Alaska
Statutes Chapter identifies as taxable “aircraft and motor
vehicles” the operation of which “relates to” the “exploration
for, production of, or pipeline transportation of gas or unre
fined oil.” Alaska Stat. § 43.56.210 (2008). Valdez claims
that its tax on ships is simply another form of this value
related tax on oil-related property.
Valdez did not make this claim in the lower courts, how
ever. Nor does the State of Alaska (which has filed a brief
in support of Valdez) support this particular claim. Brief

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14 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of Breyer, J.
for State of Alaska et al. as Amici Curiae 32–33. Thus, we
lack the State’s explanation of just how the tax on oil-related
vehicles works. And, lacking precise information, we might
ordinarily decline to consider this claim. See, e. g., Cling
man v. Beaver, 544 U. S. 581, 597–598 (2005).
Nonetheless, the parties have argued the matter in their
briefs here; and our deciding the matter now will reduce the
likelihood of further litigation. We may make exceptions to
our general approach to claims not raised below; and for
these reasons we shall do so. See Granfinanciera, S. A. v.
Nordberg, 492 U. S. 33, 39 (1989).
Addressing the claim on the basis of the briefs and what
we have gleaned from publicly available sources, we note
that Valdez’s ship tax differs from the tax on other oil-related
property in several ways. The former is a purely municipal
tax. The City imposes it; the City alone determines what
property is subject to the tax; the City establishes the rate
of taxation; the City values the property; the City resolves
evaluation disputes; the City issues assessment notices; the
City collects the tax; and the City (as far as we can tell)
keeps the revenue without any restrictions. See Valdez Mu
nicipal Code § 3.12.020(A)(1) (2008); § 3.12.060; § 3.12.020(B);
§§ 3.12.090–3.12.100; § 3.12.210(A) (2001); Valdez, Alaska,
Resolution No. 00–15, App. to Pet. for Cert. 53a–56a.
The latter is primarily a state-level tax. The State im
poses it. In fact, Valdez’s city manager characterized the
oil-property tax as involving “property taxed by the State
. . . and [raising revenue] subsequently shared with the City.”
App. 46 (affidavit of Dave Dengel). In addition, the State
determines the type of property subject to the tax; the State
forbids the municipality to exempt any property it desig
nates as taxable; the State regulates the rate of taxation
that may be applied to property it designates as taxable; the
State issues assessment notices; the State resolves evalua
tion disputes; and the State, while permitting the municipal
ity to set the precise tax rate and to collect the tax, im

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15 Cite as: 557 U. S. 1 (2009)
Opinion of Breyer, J.
poses certain kinds of limits upon the amount of the result
ing revenue that the municipality may raise that, in effect,
provide a check against excessive rates. See Alaska
Stat. § 43.56.010(b) (2008); § 43.56.210(5)(A); 15 Alaska
Admin. Code § 56.010 (2009); §§ 56.015– 56.040; Alaska
Stat. §§ 29.45.080(b), (c) (2008); § 43.56.010(c).
These differences matter. For one thing, they mean that
any ordinary oil-related business, other than ships, that finds
the tax imposed upon its movable property too burdensome
must complain to the State, not to the City, for it is the State
that is in charge of setting the manner of assessment and
valuation. At the same time, an oil tanker that finds the
vessel tax too burdensome must complain to the City, not to
the State, for the State has nothing to do with the rate, valu
ation, or assessment of that particular tax.
For another thing, they mean that there is no effective
electorate-related check (comparable to the check available
where a property tax is more broadly imposed) upon the
City’s vessel-taxing power. The City’s property tax hits
ships and only ships; it is not constrained by any need to
treat ships and other business property alike. Taken to
gether, these two considerations mean that Valdez’s property
tax lacks the safeguards implied by this Court’s statements
that a property tax on ships escapes the scope of the Ton
nage Clause only when that tax is imposed upon ships “in the
same manner” as it is imposed on other forms of property.
The Chief Justice contends that a State may never im
pose a property tax on a vessel belonging to a citizen of an
other State, even if that vessel is taxed in the “same manner”
as other personal property in the taxing State. See post, at
17–18 (opinion concurring in part and concurring in judg
ment). But, as The Chief Justice concedes, this Court
held in the State Tonnage Tax Cases and Wheeling that
vessels belonging to a State’s own citizens may be subject to
a property tax when the vessels are taxed in the same man
ner as other personal property owned by citizens of that

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16 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of Breyer, J.
State. At the time those cases were decided, the home port
doctrine was still in effect, which meant that vessels were
taxable solely by the owner’s domicil State. Since the State
Tonnage Tax Cases and Wheeling, the home port doctrine
has been abandoned, and States are now permitted to tax
vessels belonging to citizens of other States that develop
a tax situs in the nondomiciliary State, provided the tax
is fairly apportioned. See, e. g., Ott v. Mississippi Valley
Barge Line Co., 336 U. S. 169, 172–174 (1949); Japan Line,
441 U. S., at 442–443. Given this evolution in the law gov
erning interstate taxation since our decisions in the State
Tonnage Tax Cases and Wheeling, there is little reason to
think that the ability of a State to tax vessels in the “same
manner” as other personal property applies only to vessels
owned by citizens of the taxing State. In any event, we
need not decide this issue because it is clear that the vessels
subject to the City’s ordinance are not taxed in the same
manner as other personal property.
As far as we can tell, then, Valdez applies a value-based
personal property tax to ships and to no other property at
all. It does so in order to obtain revenue for general city
purposes. The tax, no less than a similar duty, may (depend
ing upon rates) “ta[x] the consumption” of those in other
States. See 3 Records of the Federal Convention of 1787,
at 519 (reprinting letter from James Madison to Professor
Davis, 1832). It is consequently the kind of tax that the
Tonnage Clause forbids Valdez to impose without the consent
of Congress, consent that Valdez lacks.
* * *
We conclude that the tax is unconstitutional. We reverse
the contrary judgment of the Supreme Court of Alaska.
And we remand the case for further proceedings.
It is so ordered.

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17 Cite as: 557 U. S. 1 (2009)
Opinion of Roberts, C. J.
Chief Justice Roberts, with whom Justice Thomas
joins, concurring in part and concurring in the judgment.
I agree with the Court’s conclusion that the Valdez tax is
unconstitutional “[b]ecause the imposition of the tax depends
on a factor related to tonnage and that tonnage-based tax is
not for services provided to the vessel.” Ante, at 10. The
plurality goes on, however, to reject the city’s argument that
the tax may be sustained as a property tax similar to ones
the city imposes on other property. The plurality rejects
that argument on the ground that the city in fact does not
impose similar taxes on other property. Ante, at 11–16.
I would instead reject the argument on the ground that it
does not matter.
The Tonnage Clause applies to “any Duty of Tonnage,” re
gardless of how that duty compares to other commercial
taxes. U. S. Const., Art. I, § 10, cl. 3. The free flow of mari
time commerce was so important to the Framers that they
grouped the prohibition on tonnage duties with bans on keep
ing troops or ships of war, entering into compacts with other
States or foreign powers, and engaging in war. Ibid. In
light of the Framers’ goal to promote trade, and the language
of the Clause, I do not see how an unconstitutional tax on
maritime commerce becomes permissible when bundled with
taxes on other activities or property. If States wish to use
their geographical position to tax national maritime com
merce, they must get Congress’s consent—just as they must
to engage in the other activities prohibited by Clause 3.
The majority responds that nothing in the history of the
Clause, its purpose, or this Court’s interpretation of it sug
gests that it bans all taxes on vessels using a port. Ante,
at 9. The majority’s list of interpretive tools tellingly leaves
out one—the words the Framers used. The Clause by its
terms provides that “No State shall, without the Consent of
Congress, lay any Duty of Tonnage.” U. S. Const., Art. I.,
§ 10, cl. 3 (emphasis added). The majority correctly con

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18 POLAR TANKERS, INC. v. CITY OF VALDEZ
Opinion of Roberts, C. J.
cludes that the Valdez tax is a tonnage duty, ante, at 10, and
that should be the end of the matter.
The majority also objects that this approach would give
vessels “preferential treatment,” when the Clause only pro
tects vessels from discrimination. Ante, at 9. But the
Clause says nothing about discrimination, and it should
hardly come as a surprise that a constitutional ban on ton
nage duties would give preferential treatment to vessels.
Such protection reflects the high value the Framers placed
on the free flow of maritime commerce. See State Tonnage
Tax Cases, 12 Wall. 204, 214 (1871) (“Prior to the adoption of
the Constitution the States . . . levied duties on imports and
exports and duties of tonnage, and it was the embarrass
ments growing out of such regulations and conflicting obli
gations which mainly led to the abandonment of the Confed
eration and to the more perfect union under the present
Constitution”).
The plurality appears to be driven to its tax-comparison
analysis only in responding to the city’s contention that the
tax is exempt from the Tonnage Clause under the State Ton
nage Tax Cases, supra, and Transportation Co. v. Wheeling,
99 U. S. 273 (1879). Neither of those cases has any bearing
here. Both cases make clear that they apply only to taxa
tion of property owned by citizens of the State. See State
Tonnage Tax Cases, supra, at 213 (referring to “[t]axes lev
ied by a State upon ships and vessels owned by the citizens
of the State” (emphasis added)); Wheeling, supra, at 284
(“Property . . . when belonging to a citizen of the State living
within her territory . . . is the subject of State taxation”
(emphasis added)). We have never held that the Tonnage
Clause allows such property taxes to be imposed on visiting
ships. Doing so would allow easy evasion of the important
principles of the Clause.
Both the plurality and Justice Stevens suggest that the
evolution of the “home port doctrine” sheds light on how to

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19 Cite as: 557 U. S. 1 (2009)
Opinion of Alito, J.
read the Tonnage Clause. See ante, at 15–16; post, at 22,
n. 1 (dissenting opinion). I disagree. Under the home port
doctrine, Polar Tankers “could not be taxed in [Valdez] at
all,” even if the tax were not a tonnage duty. Japan Line,
Ltd. v. County of Los Angeles, 441 U. S. 434, 442 (1979); Hays
v. Pacific Mail S. S. Co., 17 How. 596, 599 (1855). In con
trast, the Tonnage Clause forbids only tonnage duties, and
would permit Valdez to impose other taxes on visiting
ships—for example, “a reasonable charge for” the service of
“policing of a harbor.” Clyde Mallory Lines v. Alabama ex
rel. State Docks Comm’n, 296 U. S. 261, 267, 266 (1935). The
demise of the home port doctrine is in no way inconsistent
with reading the Tonnage Clause, as written, to ban all ton
nage duties. See Japan Line, supra, at 439, n. 3 (rejecting
home port doctrine while expressly not reaching Tonnage
Clause argument).
In any case, because the Court has determined that Val
dez’s tax is unlike other municipal taxes, it does not decide
whether a tonnage duty would be unconstitutional when
other similar property is taxed. See ante, at 16; post this
page and 20 (Alito, J., concurring in part and concurring in
judgment). Whatever other taxes the city might impose,
this tax “operate[s] to impose a charge for the privilege of
entering . . . or lying in” the port of Valdez, and is a duty of
tonnage for that reason. Clyde Mallory, supra, at 265–266.
I therefore concur in the judgment.
Justice Alito, concurring in part and concurring in the
judgment.
I join the opinion of the Court, except for Part II–B–2,
which might be read to suggest that the tax at issue here
would be permitted under the Tonnage Clause if the tax
were a property tax levied in the same manner on other per
sonal property within the jurisdiction. It is sufficient for
present purposes that the Valdez tax is not such a personal

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20 POLAR TANKERS, INC. v. CITY OF VALDEZ
Stevens, J., dissenting
property tax and therefore, even if the Tonnage Clause per
mits a true, evenhanded property tax to be applied to ves
sels, the Valdez tax is an unconstitutional duty of tonnage.
Justice Stevens, with whom Justice Souter joins,
dissenting.
The Tonnage Clause prohibits the States and their political
subdivisions from charging ships for the privilege of using
their ports. Because this case does not involve such a
charge, I respectfully dissent.
I
The Tonnage Clause commands that “No State shall, with
out the Consent of Congress, lay any Duty of Tonnage.”
U. S. Const., Art. I, § 10, cl. 3. As the Court asserts, the
purpose of the Clause is to prevent States with convenient
ports from abusing the privileges their natural position af
fords. See ante, at 7. Thus, the pertinent inquiry in deter
mining whether an exaction violates the Clause’s prohibi
tions is whether the charge is “ ‘in its essence a contribution
claimed for the privilege of arriving and departing from a
port.’ ” Transportation Co. v. Wheeling, 99 U. S. 273, 283–
284 (1879) (quoting Cannon v. New Orleans, 20 Wall. 577, 581
(1874)); see Clyde Mallory Lines v. Alabama ex rel. State
Docks Comm’n, 296 U. S. 261, 265–266 (1935). In applying
that principle, we have been cognizant of its limits.
By its terms, the Tonnage Clause prohibits States from
imposing a duty on ships based on their internal cubic capac
ity, see id., at 265, and it similarly prohibits charges that
“effect the same purpose” as a duty of tonnage—for instance,
by imposing a duty based “on the number of masts, or of
mariners, the size and power of the steam-engine, or the
number of passengers which she carries,” Passenger Cases, 7
How. 283, 458–459 (1849) (opinion of Grier, J.). By contrast,
charges levied for other purposes are outside the Clause’s

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21 Cite as: 557 U. S. 1 (2009)
Stevens, J., dissenting
reach. This Court has often approved charges for services
rendered to ships to ensure their safe and convenient use of
a port. See Clyde Mallory, 296 U. S., at 266–267. And the
federal interest in protecting access to the ports generally
does not prevent States from charging shipowners those
taxes and fees that the States are also authorized to levy on
other property. See Wiggins Ferry Co. v. East St. Louis,
107 U. S. 365, 375, 376 (1883) (upholding a “license tax” “laid
upon the business of keeping a ferry”); Wheeling, 99 U. S., at
279 (upholding a property tax on ships).
More than a century ago, we noted that it was “too well
settled to admit of question that taxes levied by a State,
upon ships or vessels owned by the citizens of the State, as
property, based on a valuation of the same as property, to
the extent of such ownership, are not within the prohibition
of the Constitution.” Ibid. Just as “[d]raymen may be
compelled to pay a license tax on every dray owned by them,
hackmen on every hack, [and] tavernkeepers on their taverns
in proportion to the number of the rooms which they keep
for the accommodation of guests,” so too can a State charge
the operator of a ferry a “tax upon the boats which he em
ploys.” Wiggins Ferry, 107 U. S., at 375. “[V]essels of all
kinds are liable to taxation as property in the same manner
as other personal property owned by citizens of the State.”
Wheeling, 99 U. S., at 284; State Tonnage Tax Cases, 12 Wall.
204, 212–213 (1871).
From Wheeling and the State Tonnage Tax Cases, two
principles emerge regarding the circumstances under which
States may levy property taxes on ships. First, the State
seeking to levy the tax must show that the ship has sufficient
contacts with the jurisdiction to establish a tax situs there.
In our earlier cases, the existence of the situs was deter
mined by the citizenship of the ship’s owner, see Wheeling,
99 U. S., at 279; State Tonnage Tax Cases, 12 Wall., at 213,
but a tax situs can also be created by a property’s substantial

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22 POLAR TANKERS, INC. v. CITY OF VALDEZ
Stevens, J., dissenting
contacts with a jurisdiction.1 The requirement of a tax situs
serves to distinguish property taxes from fees charged for
the privilege of entering a port, which the Court has consist
ently found to violate the prohibition against duties of ton
nage. See, e. g., Cannon, 20 Wall., at 581 (holding unconsti
tutional “a tax upon every vessel which stops” in the city’s
jurisdictional waters); Steamship Co. v. Portwardens, 6 Wall.
31, 33 (1867) (invalidating a tax imposed “upon every ship
entering the port” and “collected upon every entry”).
Our cases also require that property taxes on ships, as
with other property, be calculated based on the ship’s value.
When a State levies a property tax on ships, the prohibition
of the Tonnage Clause comes into play only if the ships are
“not taxed in the same manner as the other property of the
citizens, or where the tax is imposed upon the vessel as an
instrument of commerce, without reference to the value as
property.” Wheeling, 99 U. S., at 284. Although the mean
ing of Wheeling’s “same manner” language is not immedi
1 Previously, courts followed the common-law “home port” doctrine, pur
suant to which a ship could be taxed only by the State in which its owner
was domiciled. See Pullman’s Palace Car Co. v. Pennsylvania, 141 U. S.
18, 23–24 (1891). That doctrine has since “yielded to a rule of fair appor
tionment among the States,” permitting any jurisdiction with which a ship
has had sufficient contacts to establish a tax situs to levy a property tax
on the ship in proportion to the ship’s contacts with the jurisdiction. See
Japan Line, Ltd. v. County of Los Angeles, 441 U. S. 434, 442–443 (1979);
see also Standard Oil Co. v. Peck, 342 U. S. 382, 383 (1952). We have
roundly rejected the doctrine in cases involving ships moving in interstate
operations along the inland waters. See ibid. And in the context of
ocean-going ships, we have referred to the doctrine as “ ‘anachronistic’ ”
and all but “ ‘abandoned,’ ” noting that “to rehabilitate the ‘home port doc
trine’ as a tool of Commerce Clause analysis would be somewhat odd.”
Japan Line, 441 U. S., at 443. In light of these developments, it is odd
indeed that The Chief Justice endeavors to distinguish Transportation
Co. v. Wheeling, 99 U. S. 273 (1879), and the State Tonnage Tax Cases, 12
Wall. 204 (1871), as “apply[ing] only to taxation of property owned by
citizens of the State.” See ante, at 18 (opinion concurring in part and
concurring in judgment).

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23 Cite as: 557 U. S. 1 (2009)
Stevens, J., dissenting
ately apparent, the remainder of the opinion emphasizes the
importance of the method by which the tax on the petition
er’s ships was calculated—i. e., “based on a valuation of the
same as property”—rather than the city’s taxation of other
property in the jurisdiction. Id., at 279; see id., at 284.
Our decision in the State Tonnage Tax Cases is to the same
effect, as we held that taxes levied on ships “as property,
based on a valuation of the same as property, are not within
the prohibition of the Constitution,” but if States tax ships
“by a tonnage duty, or indirectly by imposing the tax upon
the master or crew, they assume a jurisdiction which they
do not possess.” 12 Wall., at 213, 214 (emphasis in original).
Indeed, each of the taxes challenged in that case was in
validated because it was “levied on the steamboats wholly
irrespective of the value of the vessels as property, and
solely and exclusively on the basis of their cubical contents.”
Id., at 217; see id., at 224 (holding the tax unconstitutional
because “the amount of the tax depends upon the carry
ing capacity of the steamboat and not upon her value as prop
erty”).2 Thus, in both Wheeling and the State Tonnage
Tax Cases, the method by which the challenged tax was
calculated was essential to the Court’s determination of its
validity.
The tax in this case has both of the critical characteristics
of a legitimate property tax. It is undisputed that petition
er’s ships “are taxed based on their value, and only those
[ships] that have acquired a taxable situs in Valdez are
taxed.” 182 P. 3d 614, 622 (Alaska 2008). Accordingly,
2 The Court seems to conflate these methods of calculating taxes on
ships, as it asserts that “a tax on the value of such vessels is closely corre
lated with cargo capacity” and concludes that the tax in this case “depends
on a factor related to tonnage.” Ante, at 10; see also ante, at 17 (opinion
of Roberts, C. J.). This is contrary to our longstanding recognition that
a ship’s capacity is not a proxy for its value: “[T]he experience of every
one shows that a small steamer, new and well built, may be of much
greater value than a large one, badly built or in need of extensive repairs.”
State Tonnage Tax Cases, 12 Wall., at 224.

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24 POLAR TANKERS, INC. v. CITY OF VALDEZ
Stevens, J., dissenting
I would uphold the Alaska Supreme Court’s decision sustain
ing the tax against petitioner’s Tonnage Clause challenge.
The plurality reaches the opposite conclusion because it
reads Wheeling’s “same manner” language to impose a dif
ferent limitation on the States’ power to tax ships. Accord
ing to the plurality, “in order to fund services by taxing
ships, a State must also impose similar taxes upon other
businesses.” Ante, at 12. As discussed above, Wheeling
and the State Tonnage Cases are better read to require that
property taxes on ships be assessed based on the value of
the ship rather than its tonnage. But even if the “same
manner” requirement did not clearly refer to the method of
calculating the tax, the phrase could not bear the weight the
plurality places on it. And there is no other support in our
cases or in the text of the Tonnage Clause for a rule that
conditions a State’s exercise of its admitted authority to levy
property taxes on ships upon its decision also to tax other
property within its jurisdiction.
Under the plurality’s reading, the same tax could be a
“Duty of Tonnage” in one instance and not in another de
pending on taxing decisions wholly outside the Clause’s
reach. Far from being compelled by our earlier cases, this
rule is in tension with our decisions noting the substantial
flexibility States must be afforded in making taxing decisions
and cautioning courts not to “subject the essential taxing
power of the State to an intolerable supervision.” Ohio Oil
Co. v. Conway, 281 U. S. 146, 159 (1930). That tension is
compounded by the inevitable difficulty States will have in
navigating the new rule, as the plurality does not suggest at
what point a State can be satisfied that it has taxed enough
other property that it may also tax ships without violating
the Clause’s prohibitions.
In support of its understanding of the “same manner” re
quirement, the plurality asserts that the rule “helps to en
sure that a value-related property tax differs significantly
from a graduated tax on a ship’s capacity and that the former

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25 Cite as: 557 U. S. 1 (2009)
Stevens, J., dissenting
is not simply a redesignation of the latter.” Ante, at 12.
But our cases provide such assurance without resort to the
plurality’s strained reading. Because States and their polit
ical subdivisions only have authority to tax property that
has established a tax situs in the jurisdiction, they cannot
levy such taxes on ships merely for the privilege of enter
ing or leaving the port; much more substantial contact with
the jurisdiction is required. See Valdez Municipal Code
§ 3.12.020(C) (2008); Central R. Co. of Pa. v. Pennsylvania,
370 U. S. 607, 614–615 (1962). And it is that contact, rather
than entry into the port, that provides the basis for taxing
the ships. The tax situs requirement thus ensures that a
State cannot avoid the proscriptions of the Tonnage Clause
by redesignating a duty charged for the privilege of entering
the port as an ad valorem tax.
The facts of this case illustrate the point. Most of peti
tioner’s ships spend 40 to 50 days per year in the Port of
Valdez. See App. 32–45. “[A]s a group the tankers form a
continuous presence in the city.” 182 P. 3d, at 623. The
ships’ prolonged physical presence and extensive commercial
activities in the city have a substantial impact on the city’s
resources. On average, the ships’ presence adds 550 people
to the population of Valdez, increasing the city’s total popula
tion by 10%. Those people, as well as the ships themselves,
require numerous public services, including harbor facilities,
roads, bridges, water supply, and fire and police protection.
Ibid. As the Alaska Supreme Court concluded, the chal
lenged tax is therefore a legitimate property tax levied to
support the ships’ use of the city’s services. See ibid.
II
Even if the Tonnage Clause were properly understood to
permit a jurisdiction to levy a tax on ships only when other
property in the jurisdiction is also taxed, I would uphold the
challenged tax. Although the tax applies only to ships, see

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26 POLAR TANKERS, INC. v. CITY OF VALDEZ
Stevens, J., dissenting
Valdez Municipal Code § 3.12.020, other property in the city
is also subject to taxation.
First, § 3.12.022 imposes a value-based property tax on
trailers, mobile homes, and recreational vehicles that are af
fixed to a site and connected to utilities. The plurality
makes much of the requirement that the property be “ ‘af
fixed’ ” to a particular site, concluding that “Valdez in fact
taxes those vehicles only when they constitute a form, not
of personal property, but of real property.” Ante, at 13.
But the taxability of property pursuant to § 3.12.022 is de
termined in much the same way as the taxability of ships.
“A trailer or mobile home is conclusively presumed to be
affixed to the land” and may therefore be taxed if “it
has remained at a fixed site for more than ninety days.”
§ 3.12.022(C). Similarly, a shipowner can establish a tax
situs in Valdez and thus be subject to taxation if its ship is
“kept or used within the city for any ninety days or more.”
§ 3.12.020(C)(2)(c).3 In both cases, the provision serves to
impose a tax on property that has developed substantial con
tacts with the city. The plurality is thus wrong to conclude
that ships have been singled out for taxation.
Valdez also “levie[s] a tax” on all property taxable under
Alaska Statutes Chapter 43.56 at the same rate that applies
to other property taxed by the city. Valdez Municipal Code
§ 3.28.010.4 The tax is imposed on property used “primarily
in the exploration for, production of, or pipeline transporta
tion of gas or unrefined oil,” including machinery, equipment,
pumping stations, powerplants, aircraft and motor vehi
cles, and docks and other port facilities. See Alaska Stat.
3 A ship can also establish a tax situs in Valdez if it is usually kept or
used within the city, travels to or within the city along regular routes,
or is necessary to the conduct of substantial business in the city.
§ 3.12.020(C)(2).
4 As the plurality notes, ante, at 13–14, Valdez did not raise this issue
in state court, and the parties have provided only limited briefing on the
issue.

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27 Cite as: 557 U. S. 1 (2009)
Stevens, J., dissenting
§§ 43.56.010, 43.56.210(5)(A) (2008). For several reasons,
this tax is more significant than the plurality acknowledges.
First, contrary to the plurality’s view, the tax appears to be
a municipal tax. Valdez Municipal Code § 3.28.010 states
that the tax “is hereby levied” on “property taxable under
Alaska Statutes Chapter 43.56,” which in turn states that
“[a] municipality may levy” such taxes, § 43.56.010(b). The
terms of these provisions indicate that the city has exercised
its express authority to levy such taxes. Given the myriad
types of property taxable under those provisions and the re
quirement of Valdez Municipal Code § 3.28.010 that the prop
erty be taxed “at the rate of taxation that applies to other
property taxed by the city,” it seems clear that petitioner’s
ships are taxed in the “same manner” as other property even
as the plurality uses that term.
My view of the case would be the same even if the tax on
property used in oil production were imposed by the State
itself, as the plurality assumes. Whether the oil-production
tax and the challenged tax are levied by the same unit of
government has no relevance to the question whether the
latter violates the Constitution. The restriction imposed by
the Tonnage Clause is a command to the States limiting their
inherent taxing authority as sovereigns. The States’ politi
cal subdivisions have no such inherent power and can levy
taxes only to the extent authorized by the State. See 16 E.
McQuillin, Law of Municipal Corporations § 44.05, pp. 19–24
(rev. 3d ed. 2003); see also Wiggins Ferry, 107 U. S., at 375
(noting “[t]he power of [a State] to authorize any city within
her limits to impose a license tax” on ferries). Indeed, this
aspect of the relationship between States and their political
subdivisions is reflected in Alaska Stat. § 43.56.010(b), which
authorizes municipalities to levy certain taxes and prevents
them from exempting particular property from taxation.
Because the city’s power to levy taxes derives from the
State, whether the city or the State levies the tax on oil
production property is constitutionally irrelevant.

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28 POLAR TANKERS, INC. v. CITY OF VALDEZ
Stevens, J., dissenting
Finally, it bears mention that the result in this particular
case does nothing to further the interests the Tonnage
Clause was intended to protect. As the Court acknowl
edges, ante, at 7, the central purpose of the Clause is “to
prevent the seaboard States, possessed of important ports of
entry, from levying taxes on goods flowing through their
ports to inland States,” Youngstown Sheet & Tube Co. v.
Bowers, 358 U. S. 534, 556 (1959) (Frankfurter, J., dissenting
in part). Port Valdez is at the southern terminus of the
Trans Alaska Pipeline System, which carries oil extracted
from Alaska’s North Slope to Port Valdez where it is loaded
onto oil tankers belonging to petitioner and others for trans
port to refineries in other States. Taxes imposed on ships
exporting that oil have the same effect on commerce in oil
as do taxes on oil-production property or the oil itself, and
Alaska’s authority to impose taxes on oil and oil-production
property is undisputed. From an economic or political point
of view, there is no difference between Alaska’s geographical
control over the area in which the oil is produced and the
port from which it is exported. Accordingly, no federal in
terest is served by prohibiting Alaska or its political subdivi
sions from taxing the oil-bearing ships that are continually
present in the State’s ports.
III
The Tonnage Clause permits a State to levy a property
tax on ships whether or not it taxes other property. Were
that not the case, the challenged tax would still be permissi
ble because Valdez also taxes mobile homes, trailers, and a
wide variety of property used in producing oil. Because the
tax in my view does not run afoul of the prohibitions of the
Tonnage Clause, I respectfully dissent.