In the chief case challenging tariffs issued under the International Emergency Economic Powers Act of 1977 (IEEPA), part of President Donald Trump’s tariff policies had its day in the Supreme Court Wednesday.
The case, filed by V.O.S. Selections, Inc. and other plaintiffs, and joined by several states, challenges the president’s power to impose tariffs such as the IEEPA tariffs on China, the 10% tariffs on certain products from Canada and Mexico and the worldwide 10% tariffs. On May 28, 2025, the U.S. Court of International Trade decided the case in favor of the plaintiffs and found that the president’s tariffs had gone too far and were unconstitutional. The lower court issued an injunction against the IEEPA tariffs, giving the Trump Administration ten days to appeal its decision.
The administration appealed that decision to the Federal Circuit Court of Appeals, which, on Aug. 29, 2025, affirmed the underlying decision that the tariffs were unconstitutional. The administration appealed the decision again to the Supreme Court, which agreed to hear the case on an expedited timeline.
Wednesday, the Supreme Court heard oral arguments on the IEEPA challenge. While Supreme Court arguments have ballooned in length since the court made changes to its argument structure during COVID, Wednesday's argument was still unusually long. Last term, arguments averaged around an hour and a half. Wednesday’s argument went for nearly three hours, with most justices questioning both sides in lengthy exchanges.
While some of the justices’ questions consistently leaned in one direction or another, both sides faced sharp questioning, particularly from Chief Justice Roberts and Justices Barrett and Gorsuch. Questions and arguments focused on IEEPA’s statutory language permitting the president to “regulate . . . importation” and whether a broad authority to levy tariffs is encompassed by this law.
Neal Katyal, representing the parties challenging the tariffs, argued that because a tariff is essentially a tax, this power belongs to Congress under Article 1 of the Constitution and cannot be delegated to the president. The solicitor general, in defending the tariffs on behalf of the Administration, argued the opposite: Tariffs are not intended to raise revenue and are thus more appropriately thought of as a means to regulate foreign affairs, which is a realm of policy delegated to the president under Article 2 of the Constitution.
The justices raised other concerns, too. Justice Gorsuch appeared particularly troubled with what he called a “one-way rachet” in the administration’s argument. He made the practical point that if the court were to decide that Congress intended to grant the president the ability to levy these tariffs, there would then be no practical way for Congress to ever claw this power back, as any president would hold a veto power over any such claw-back legislation.
Justice Barrett questioned the challengers regarding the feasibility of their requested relief: a refund process, raising concerns with the size of refund claims and the practicability of administering such a program.
Justice Kavanaugh focused on President Nixon’s invocation of the power to “regulate importation” under IEEPA’s predecessor statute in issuing a set of tariffs in 1971, suggesting this might be evidence that Congress was aware this statutory language could be invoked to authorize tariffs at the time it passed IEEPA.
Several justices also questioned the parties on the extent to which the “major questions doctrine” should play a role in the case. Those challenging the tariffs argued that the doctrine — which the court recently invoked to hold that Congress could only delegate governmental powers touching on “major questions” to the executive branch with a clear delegation of authority — means if Congress intended for IEEPA to grant the president the ability to issue tariffs, it would have said so clearly.
While oral argument revealed some justices’ leanings and primary areas of concern, a clear majority either in favor of or against the administration’s tariff authority did not emerge.
Given the Supreme Court’s agreement to expedite a decision in this case, a decision could be issued before the end of the year. Whatever the decision, it will have a broad effect on the administration’s current tariffing regime. All tariffs issued under IEEPA are potentially impacted. However, tariffs issued under Section 232 are not at issue in this case.
