The Supreme Court Takes Aim at Trump’s IEEPA Tariffs

John K. Veroneau served as deputy U.S. trade representative under President George W. Bush and assistant secretary of defense under President Bill Clinton. He is an adjunct faculty member at the University of Maine School of Law.

Last week, the U.S. government argued to the Supreme Court that tariffs imposed by President Donald Trump under the International Economic Emergency Act (IEEPA) were lawful because they are regulatory rather than revenue-raising. Given the president’s public claims that the tariffs have raised massive sums, however, that argument is unlikely to convince the court.

The regulatory-versus-revenue distinction is a difficult needle to thread, but the government will need to if it hopes to prevail. It needs to show that IEEPA delegates authority broadly enough to allow the president to any impose tariffs he deems fit, but not so broad that IEEPA constitutes an unconstitutional delegation of congressional powers. To reiterate: this a difficult needle to thread.

IEEPA enables the president to take certain actions to “deal with ... an unusual and extraordinary threat to U.S. national security, foreign policy, or economy originating from outside the United States.” The list of actions the president can take does not include tariffs. The government argues that IEEPA allows the president to “regulate ... importation,” which implicitly includes tariffs. Most members of the court seem unpersuaded.

Congress zealously guards its exclusive tariff-raising authority, delegating it to presidents only under clearly prescribed conditions. Congress likely did not intend IEEPA to provide the president authority to arbitrarily impose any tariff at any time, as the government argues. As Justice Neil Gorsuch noted at the hearing, reading tariff authority into IEEPA so broad that all other tariff authorities would be rendered superfluous seems highly unlikely.

The government further argued that the president’s undisputed right to completely block imports implicitly includes authority to take less drastic steps such as imposing tariffs. This, too, seems unlikely.

First, a tool that enables trillions of dollars to be raised is not a lesser tool than one that does not. Secondly, blocking imports is more consistent with IEEPA’s purpose of enabling the president to respond quickly to foreign threats. Tariffs, on the other hand, are a comparatively weak response to an “unusual and extraordinary threat,” especially as tariffs are largely paid by Americans.

Beyond the government’s claim that IEEPA grants the president unbound authority to impose tariffs, it also claims that the president’s reasoning for imposing those tariffs is not reviewable by courts. Taken together, those two claims would render IEEPA an unconstitutional grant of authority.

The U.S. Constitution provides Congress with the exclusive authority to determine tariff levels. Presidents must rely on statutory authority provided by Congress to raise tariffs because they have no independent power to do so. However, Congress cannot grant the president a blank check to impose tariffs as he sees fits; doing so would violate Article I of the Constitution, which bars Congress from transferring its lawmaking authority to the president without clear limits.

To avoid its interpretation of IEEPA being declared an unconstitutional delegation of power, the government has argued that the IEEPA tariffs at issue are regulatory rather than revenue-raising in nature.

Chief Justice John Roberts seemed doubtful of that interpretation, and would likely draft the majority opinion and be joined by Justices Gorsuch, Ketanji Brown Jackson, Elena Kagan, and Sonia Sotomayor. Justice Amy Coney Barrett also seemed skeptical of the government’s case, and could well join a majority decision. Justices Samuel Alito, Brett Kavanaugh, and Clarence Thomas seemed most reluctant to rule out the possibility of IEEPA tariffs.

In an effort to expand the majority, the chief justice could adopt the government’s distinction between regulatory and revenue tariffs. There is precedent for distinguishing incidental effects from major ones. For instance, the court has distinguished intrastate activities with significant impact on interstate commerce from those that have merely incidental effects. The chief justice’s institutionalist instincts could cause him to explore a broadly supported position whereby the court does not completely rule out the possibility of IEEPA tariffs so long as the revenue at stake is merely incidental, and therefore does not unavoidably violate the nondelegation clause. If the Supreme Court were to take this approach, the case could be remanded to a lower court to give the government an opportunity to show that the revenue raised by the IEEPA tariffs is merely incidental. It seems obvious that the government would be unable to demonstrate this, and the pending tariffs would need to be withdrawn.

This work represents the views and opinions solely of the authors. The Council on Foreign Relations is an independent, nonpartisan membership organization, think tank, and publisher, and takes no institutional position on matters of policy.