SCOTUS Held Against President Trump’s Tariffs:An Overview of the Opinion

By Editor-in-Chief: Eric Fogle

On February 20, 2026, the Supreme Court decided that President Trump exceeded his authority by imposing tariffs under the International Emergency Economic Powers Act (IEEPA). This article traces the legal issues, arguments, and ultimate conclusion of the Court. The opinion is a fascinating read, and constitutional law conversations about presidential authority and the separation of powers.

The question before the Court was whether the IEEPA appropriately authorized the President to impose tariffs.

Trump based his tariffs on two threats. The first threat was an influx of dangerous and illegal drugs from Canada, Mexico, and China. The second threat was identified as persistent trade deficits. President Trump later declared both threats to be national emergencies. He used his authority under the IEEPA to respond by invoking tariffs. Litigants in different cases brought suit alleging that the IEEPA does not authorize the drug trafficking and reciprocal tariffs.

The IEEPA grants the President the authority to ““investigate, block during the pendency of an investigation, regulate, direct and compel, nullify, void, prevent or prohibit . . . importation or exportation.” 50 U. S. C. §1702(a)(1)(B).

The syllabus to the opinion begins with a citation to the Taxing Clause, every constitutional law student’s favorite provision. The Government conceded that President Trump was not seeking to invoke the Taxing Clause as a basis for the tariffs. Rather, the President invoked his authority under IEEPA. The argument goes: in enacting IEEPA, Congress delegated to the Executive, authorizing the President to impose tariffs broadly. Specifically, the Government read the terms “regulate” and “importation” in Section 1702(a)(1)(B) of the IEEPA to grant the President power to impose tariffs.

The IEEPA was signed into law by former president Jimmy Carter in 1977. The Court noted that it had never been used to impose tariffs. The Court further noted that reading the IEEPA to give the President the power he seeks to invoke would expand presidential authority in an unprecedented manner. Using both the history of the law and transformation in the separation of powers implicated by the Government’s interpretation of the law, the Court found that the President exceeded the scope of his authority. Interestingly, the IEEPA was the law at issue in Dames & Moore v. Regan, 453 U.S. 654 (1981), a case most constitutional law classes will cover in their discussion of the balance of power between the legislative and executive branches. It was also cited in the dissenting opinion.

The major questions doctrine restricts regulatory authority of the Executive over economically or politically significant issues without clear congressional authorization. As Justice Gorsuch characterizes in his concurrence: “[u]nder the [major question] doctrine’s terms, the President must identify clear statutory authority for the extraordinary delegated power he claims.”

Using this doctrine, the Court opined that if Congress intended to delegate the power to impose tariffs in the IEEPA, it would not have done so using ambiguous language. The Court stressed the separation of powers, particularly the core congressional power of the purse. The Court found that there was no clear congressional authorization for President Trump to impose tariffs as he did.

In a concurrence, Justice Gorsuch addresses, among other issues, how his fellow Justices have treated the major questions doctrine in other cases vis-à-vis the current opinion.

Justice Barrett wrote a separate concurrence. Justice Kagan, joined by Justice Sotomayor and Justice Jackson, authored another concurring in part and concurring in the judgment. Justice Jackson concurred in part and concurred in the judgment.

Justice Thomas dissented, arguing that the IEEPA is consistent with the separation of powers.

Justice Kavanaugh authored the principal dissent, joined by Justice Thomas and Justice Alito. Justice Kavanaugh argues that the statute’s text, history, and precedent demonstrate that the IEEPA allows the President to regulate importation, as those terms are used in the IEEPA.