This educational guide is based on the linked primary sources. It is not a Court publication, is not affiliated with the Court, and is not legal advice.
In brief
Overview
According to Polar Tankers, Inc., according to Polar Tankers, Inc., polar Tankers, Inc. challenges the City of Valdez’s vessel tax as unconstitutional under the Tonnage Clause, the Due Process Clause, and the Commerce Clause.
The City of Valdez argues that the tax is a permissible property tax authorized by state law and does not violate the Constitution.
During oral argument, the Justices asked numerous questions about the tax’s constitutionality, its historical basis, and whether it discriminates against certain vessels or states.
- [1] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 3
- [2] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 4
- [3] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 29
- [4] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 30
- [5] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 3
- [6] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 5
- [7] 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdf, p. 20
Background and question before the Court
According to Justice Kennedy, the City of Valdez imposes a tax on vessels that is described as 11 percent of the tax base.
According to Polar Tankers, Inc., according to Polar Tankers, Inc., the central legal question is whether the vessel tax violates the Constitution’s Tonnage Clause, Due Process Clause, and Commerce Clause.
What each side argues
Polar Tankers, Inc. – Position
According to Polar Tankers, Inc., according to Polar Tankers, Inc., the tax operates as a charge on the privilege of trading in Valdez and improperly taxes extraterritorial values, violating the Due Process and Commerce Clauses.
According to Polar Tankers, Inc., according to Polar Tankers, Inc., the tax targets only certain vessels, exempting small boats and fishing vessels, making it a discriminatory property tax contrary to the Tonnage Clause.
City of Valdez, Alaska – Position
According to Rothfeld, vessels are a distinct category of property under the Tonnage Clause, and the city’s tax does not violate that clause.
What happened at oral argument
Justice Kennedy asked whether the tax’s 11 percent rate of the tax base was accurate and what it meant.
According to Justice Souter, justice Souter questioned whether the tax discriminates against certain states or vessels, potentially violating the Tonnage Clause.
Justice Scalia asked if a daily charge on vessels for remaining in port violates the Tonnage Clause.
According to Justice Stevens, justice Stevens inquired which state might be discriminated against by the tax scheme.
Chief Justice Roberts asked how a city could impose a property tax on a vessel.
What the Court decided
Why it matters
Terms to know
No glossary terms are available for this guide.
Primary sources
Read the source materials on the official site or open the immutable repository copy used for this guide.
- 56107ecd95b6564762bb-r1-879a9c1be495b32d.pdforal argument transcript
Guide generated September 23, 2026. Automated validation accepted this version.