The U.S. Supreme Court on Friday, struck down President Donald Trump’s use of the International Emergency Economic Powers Act (IEEPA) of 1977 to impose sweeping global tariffs, ruling 6-3 that the law does not authorize the president to impose tariffs.

Chief Justice John Roberts authored the majority opinion, stating that IEEPA’s grant of authority to “regulate … importation” does not include the power to impose tariffs. He emphasized that the Constitution assigns tariff-setting power to Congress, and that IEEPA contains no reference to tariffs or duties.

Roberts wrote, “The President asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope,” which requires “clear congressional authorization” under the major questions doctrine. The majority included Roberts, Sonia Sotomayor, Elena Kagan, Neil Gorsuch, Amy Coney Barrett, and Ketanji Brown Jackson.

The decision invalidated tariffs imposed under IEEPA, including a 10% baseline global tariff and higher rates on countries like China, Canada, and Mexico, which Trump justified as responses to trade deficits and the flow of illicit fentanyl.

The Court said that no prior president had interpreted IEEPA as authorizing tariffs, and that tariffs are fundamentally different from other IEEPA tools like asset freezes or sanctions because they are revenue-raising measures. Roberts stressed that Congress would not “relinquish its tariff power through vague language” and that the law’s broad interpretation would allow the president to impose duties “of unlimited amount and duration, on any product from any country.”

In a dissenting opinion, Justice Brett Kavanaugh argued that tariffs are a traditional and lawful tool for regulating importation, citing historical precedent and the fact that presidents have long used tariffs to manage trade. He warned that the ruling could lead to “substantial multi-billion-dollar refund chaos,” as the government may be required to return billions collected under the now-illegal tariffs. The court did not rule on refunds.

Kavanaugh emphasized that the major questions doctrine should not apply in foreign affairs cases and noted that Trump could still impose tariffs under other statutes, including the Trade Expansion Act of 1962 (Section 232), the Trade Act of 1974 (Sections 122, 201, 301), and the Tariff Act of 1930 (Section 338).

The legal battle began in 2025 when small businesses and a coalition of 12 states sued over the tariffs, arguing they exceeded executive authority. Lower courts had already ruled the tariffs illegal, and the Supreme Court consolidated the cases as Learning Resources Inc. v. Trump and V.O.S. Selections v. United States.

The ruling does not affect Trump’s Section 232 tariffs on steel and aluminum, which remain in place. The decision is a major setback for Trump’s economic agenda, which relied heavily on tariffs as leverage in trade negotiations.

Despite the ruling, Trump announced plans to impose a new 10% global tariff under Section 122 of the Trade Act of 1974. The government may now face billions in refund claims, with businesses like Costco, Crocs, and Revlon already seeking full reimbursement.

Following the ruling, Trump delivered a fiery press conference at the White House, calling it “deeply disappointing” and “a disgrace to our nation.” He denounced the six justices who ruled against him, accusing them of being “unpatriotic and disloyal to the Constitution,” and specifically attacked Gorsuch and Barrett, whom he appointed.

Trump vowed to reimpose tariffs using alternative legal authority, announcing plans to impose a 10% global tariff under Section 122 of the Trade Act of 1974, which allows temporary tariffs for up to 150 days without congressional approval. He stated this would be “over and above” existing tariffs.

“Therefore, effective immediately, all National Security TARIFFS, Section 232 and existing Section 301 TARIFFS, remain in place, and in full force and effect," Trump wrote in part on Truth Social. "Today I will sign an Order to impose a 10% GLOBAL TARIFF, under Section 122, over and above our normal TARIFFS already being charged, and we are also initiating several Section 301 and other Investigations to protect our Country from unfair Trading practices. The new TARIFFS, totally tested and accepted as Law, are on their way.”

Trump has since signed a new executive order on tariff. “It is my Great Honor to have just signed, from the Oval Office, a Global 10% Tariff on all Countries, which will be effective almost immediately. Thank you for your attention to this matter! PRESIDENT DONALD J. TRUMP,” he wrote late Thursday