On November 5, the Supreme Court heard oral arguments to consider the legality of two separate challenges to the president’s use of the International Emergency Economic Powers Act (“IEEPA”) to impose tariffs in the consolidated cases of Trump v. V.O.S. Selections (No. 25-250) and Learning Resources v. Trump (No. 24-1287). The oral argument provided the first indication of how the justices are viewing the president’s authority to impose tariffs. While we expect a ruling from the court on an expedited basis—perhaps even before the end of the year—the process could stretch to June 2026. The IEEPA-based tariffs will remain in effect pending the outcome of this case. While the case is pending, Treasury Secretary Scott Bessent has said that the administration will not impose new tariffs.

Throughout oral arguments, the justices seemed to be struggling with two key questions: (1) Can Congress give the president authority to issue tariffs as expansively as he has under IEEPA, and (2) Did Congress say enough to do that in IEEPA? On the first question, many of the justices expressed openness to the idea that Congress could delegate its tariff-making authority, even enough to allow President Trump to do what he has done using IEEPA. There was much more skepticism about whether Congress said enough to delegate tariff authority under IEEPA. The justices’ questioning was centered around four central themes:

1. Taxation Power vs. Authority Over Foreign Affairs. Several of the justices—including Chief Justice Roberts—noted the tension between two dueling constitutional principles. On one hand, the Constitution explicitly vests the power to impose tariffs in Congress, while on the other, the Constitution places most foreign policy powers under the executive. The justices appeared sensitive to the notion that, should they strike down the tariff regime, the executive would lose a major foreign policy instrument. At the same time, several justices—including Trump-appointed Justice Barrett—noted that the power to tariff (and tax) is a key power vested in Congress alone. Relatedly, the court continued to question whether the administration’s tariffs ought to be thought of as revenue-generating taxes or regulatory tools at the executive’s disposal for which revenue is an incidental byproduct of such regulation.
2. Statutory Interpretation. A key theme of the argument was whether the phrase “regulate importation” in IEEPA permits the president to impose tariffs. Several justices asked the administration for other examples in the U.S. Code where the word “regulate” provides the executive the power to impose taxes. However, several justices also seemed supportive of the proposition that IEEPA does not need to explicitly say the words “tariff” or “duty” to provide the executive with the authority to impose tariffs. There was also a lengthy discussion about language in IEEPA that clearly gives the president authority to regulate importation “by means of instructions, licenses or otherwise.” Justice Gorsuch and Barrett explored the possibility that this language could allow the government to “recharacterize these tariffs as licenses or rejigger the scheme so that they are licenses.”
3. Separation of Powers Principles. Underlying the statutory interpretation question are key constitutional principles designed to limit the delegation of congressional authority to the executive. Justices across the ideological spectrum repeatedly raised questions about IEEPA in light of the major questions doctrine and the nondelegation doctrine. These doctrines describe constitutional restrictions on Congress. They say that Congress cannot delegate some of its inherent powers to the executive branch, and to the extent it does delegate some of its powers on issues of significant economic or political importance, it must do so using clear and explicit language. The justices also questioned whether the fact that it would be difficult to alter or appeal IEEPA counseled for the court to adopt a narrower reading of the statute, especially where tariffs are concerned.
4. Practical Considerations. Several of the justices focused on the potential implications of invalidating the tariffs. Both Justices Alito and Barrett raised questions about potential future tariffs and how courts might require that the administration roll back the tariff regime and return funds to businesses that already paid the duties.

The decision will broadly impact the U.S. economy and global trade. The tariffs in question have generated billions of dollars in tariff revenue and reshaped diplomatic relations worldwide. If the court invalidates the tariffs, it raises the question of whether importers could be entitled to a refund—a process that poses financial and administrative challenges.

No matter how the court rules, the Trump administration appears committed to using tariffs to achieve its broader economic and foreign policy goals. In fact, the administration has recognized from the beginning that basing its tariffs on IEEPA carried with it the risk of an adverse legal decision by the Supreme Court. For that reason, President Trump launched a number of different trade investigations early in his administration that can form the basis for additional tariffs in case the Supreme Court rules against him. In recent days, administration officials like Treasury Secretary Scott Bessent have spoken openly about further developing a so-called “plan B” to maintain President Trump’s tariff policies as closely as possible to their current form if IEEPA-based tariffs are no longer an option. Tariffs will likely continue to play a central role in U.S. trade policy in the coming years. For Brownstein’s alert on the host of other tariff authorities available to the administration, please click here.

The outcome of the case remains uncertain, with many commentators saying the case is too close to call. Every justice participated actively in the lengthy oral argument. Broadly speaking, the justices fell into three groups of three. First, Justices Sotomayor, Kagan and Jackson seemed more skeptical that IEEPA gave the president authority to impose tariffs. Second, Justices Thomas, Alito and Kavanaugh seemed more open to the administration’s arguments to uphold the tariffs. The third grouping—Chief Justice Roberts and Justices Gorsuch and Barrett—carefully probed the arguments of both sides. Their votes could prove decisive.

Ordinarily, the Supreme Court often issues decisions on its most controversial cases towards the end of its term, often around June. The court considered this consolidated case on an expedited basis. So, while the court is not bound to issue its decision by a certain date, it is more likely to issue its decision more quickly than at the end of its term. U.S. Trade Representative Ambassador Jamieson Greer, for example, suggested the court’s decision could come before the end of the year.