On February 21, 2026, the U.S. Supreme Court delivered a significant ruling that invalidated some of former President Donald Trump’s most expansive tariffs. In a 6-3 decision, the Court held that Trump lacked the authority to impose these tariffs under a key emergency powers statute, the International Emergency Economic Powers Act (IEEPA). The ruling marked a rare instance of a bipartisan majority—including both liberal and conservative justices—limiting executive power in the area of trade policy.
The case centered on whether the president has the power under IEEPA to impose tariffs on imports as a means of addressing national emergencies. IEEPA, enacted in 1977, grants the president authority to “regulate … importation” during unusual and extraordinary threats to the United States’ national security, foreign policy, or economy. During his presidency, Trump invoked this law to justify tariffs on a wide array of goods from nearly every country, citing persistent trade deficits and concerns about illicit drug trafficking—particularly from China, Canada, and Mexico.
However, no prior president had ever used IEEPA to impose tariffs, and the statute itself does not explicitly mention tariffs, duties, levies, or taxes. This ambiguity became the focal point of the Supreme Court’s deliberations. Ultimately, the Court’s majority concluded that “regulate importation” does not include the power to levy tariffs, which are distinct because they directly raise revenue for the federal government by imposing duties on domestic importers.
Chief Justice John Roberts authored the majority opinion, joined by Justices Sonia Sotomayor, Elena Kagan, Neil Gorsuch, Amy Coney Barrett, and Ketanji Brown Jackson. This coalition included three conservatives and three liberals, underscoring the cross-ideological nature of the decision. Roberts emphasized that when Congress delegates tariff authority, it does so explicitly and with clear limits—none of which are present in IEEPA.
“Our task today is to decide only whether the power to ‘regulate … importation,’ as granted to the president in IEEPA, embraces the power to impose tariffs,” Roberts wrote. “It does not.” He warned against allowing the executive branch to claim sweeping tariff powers based on vague statutory language, noting that tariffs can have “astonishing” economic and political consequences. Roberts cited government projections that Trump’s tariffs could reduce the national deficit by $4 trillion and affect international agreements worth $15 trillion.
A key legal principle influencing the majority’s reasoning was the “major questions doctrine,” which requires clear congressional authorization for executive actions with vast economic or political significance. Roberts, along with Justices Gorsuch and Barrett, invoked this doctrine, stressing that the president cannot claim broad powers without explicit statutory backing. Roberts wrote that it would be unlikely for Congress to “relinquish its tariff power through vague language” without imposing constraints.
However, the justices in the majority were not entirely unified in their reasoning. While Roberts, Gorsuch, and Barrett relied heavily on the major questions doctrine, the three liberal justices—Sotomayor, Kagan, and Brown Jackson—arrived at the same conclusion through traditional statutory interpretation methods. Justice Kagan, writing a concurring opinion joined by Sotomayor and Jackson, explained that although IEEPA grants the president significant authority over foreign transactions, it conspicuously excludes the power to impose tariffs.
Kagan noted that previous presidents understood IEEPA as enabling them to regulate imports but not to levy duties, which fall under a separate statute, Title 19 of the U.S. Code. “None, as far as anyone has suggested, even considered doing otherwise,” she wrote. The liberal justices therefore viewed the statute’s silence on tariffs as decisive, rather than relying on the major questions doctrine.
In stark contrast, the dissenting opinion came from Justice Brett Kavanaugh, joined by Justices Clarence Thomas and Samuel Alito. Kavanaugh argued that the phrase “regulate … importation” in IEEPA necessarily includes tariffs, pointing to a long tradition of presidents using tariffs as a tool to regulate trade. He emphasized that tariffs, quotas, and embargoes have historically been accepted mechanisms for controlling imports, and that IEEPA empowers the president to deploy all such tools during national emergencies.
Kavanaugh further contended that the major questions doctrine did not apply in this case. He argued that the statute’s text, legislative history, and precedent provide “clear congressional authorization” for