[JURIST] The US Supreme Court [official website; JURIST news archive] on Wednesday heard oral arguments [day call, PDF; briefs] in Polar Tankers v. City of Valdez [oral arguments transcript, PDF; JURISTreport], where the Court will consider whether a municipal tax that falls exclusively on large vessels in the city’s harbor violates the Tonnage Clause (Art. 1 § 10 cl. 3), the Commerce Clause (Art. 1 § 8 cl. 3), or the 14th Amendment Due Process Clause of the US Constitution [text]. The city of Valdez, Alaska, imposes a tax on oil tankers and other large vessels using its port to pick up and deliver crude oil. The Alaska Supreme Court upheld [opinion, PDF] the tax. Counsel for Polar Tankers argued that, because the tax effectively only targeted these ships, and neither other vessels nor other property, the city had violated constitutional restrictions:

The Valdez vessel tax violates the Constitution's Tonnage Clause because it operates as a charge on a privilege of trading in the port of Valdez, and that tax is apportioned in a way that is guaranteed to tax extraterritorial values and values that do not have a connection to the city. That violates the Due Process and Commerce Clauses.

Counsel for the city argued that "no ad valorem property tax has ever been held to violate the Tonnage Clause."