In this case, the Supreme Court gave an expansive interpretation to the Constitution's Export Clause, which provides: "No Tax or Duty shall be laid on Articles exported from any State." U.S. Const., Art. I, § 9, cl. 5. The Court held that the Harbor Maintenance Tax (HMT), 26 U.S.C. § 4461, which levied an ad valorem charge on shipments at the nation's ports, violated this clause as applied to exports. As the Court noted, this decision will impact thousands of currently pending cases.
The HMT, which applies uniformly to exporters, importers and domestic shippers, imposes a charge set at a percentage of the cargo's value. United States Shoe challenged the statute under the Export Clause and won both in the Court of International Trade and the Federal Circuit. The United States argued before the Supreme Court that, despite its name and its placement in the Internal Revenue Code, the HMT was not a "tax" under the Export Clause, but instead a permissible user fee.
The Supreme Court rejected this argument, affirming the lower court in a unanimous opinion authored by Justice Ginsburg. The Court found that the HMT was a tax, not a user fee, because it was based on the value of the shipments rather than of the services that the government rendered. The Court distinguished "user fee" cases under other constitutional provisions, holding that those constitutional mandates are less exacting than the Export Clause.