The U.S. Supreme Court ruled on Friday that many of Donald Trump’s global tariffs were illegal, delivering a sharp rebuke to one of his signature economic policies. In a 6-3 decision, the court said a 1977 law designed for national emergencies did not give Trump the authority to impose most of the tariffs on countries around the world. This marks the first time the Supreme Court has overturned a second-term policy of the former president. Trump criticized the justices at a press conference, calling them “a disgrace to the nation.” He announced that the administration would immediately enact a new 10% global baseline tariff under Section 122 of the Trade Act of 1974. This law allows the president to impose tariffs for up to 150 days while investigations into unfair trading practices are conducted. He said the ruling “made a president’s ability to regulate trade more powerful and crystal clear” and claimed the new tariffs would protect U.S. companies and increase national income. The court’s decision challenged one of Trump’s boldest assertions of executive power. During his presidency, Trump used tariffs aggressively to reshape U.S. trade policy, overturning long-standing agreements and collecting tens of billions of dollars from companies importing foreign goods. Traditionally, tariffs must be approved by Congress, which alone has the constitutional authority to levy taxes. Trump argued that he could impose the tariffs under the International Emergency Economic Powers Act (IEEPA), a law that allows the president to control international transactions during national emergencies. The Supreme Court rejected this reasoning, noting that the power to levy tariffs during peacetime rests solely with Congress. The justices referenced the Constitution’s framers, who emphasized that the taxing power—including tariffs—belongs to Congress. The court also applied the “major questions doctrine,” which requires clear congressional authorization for executive actions that have broad economic effects. Because the administration had no explicit legal approval, the tariffs were struck down. The ruling highlighted that the president “cannot rely on ambiguous language in laws passed by Congress” to justify such actions. The three liberal justices—Sonia Sotomayor, Elena Kagan, and Ketanji Brown Jackson—joined Chief Justice John Roberts, Neil Gorsuch, and Amy Coney Barrett, both Trump appointees, in the majority. Justice Brett Kavanaugh dissented, arguing the ruling would not greatly restrict presidential tariff authority in the future, as Trump had only “checked the wrong statutory box” under IEEPA. He noted that the decision could create complex issues regarding refunds of billions of dollars collected under the illegal tariffs. Economists have warned that Trump’s tariffs risk raising prices for Americans after years of high inflation, despite claims that tariffs would revitalize U.S. industries and make global trade fairer. Senate Minority Leader Chuck Schumer called the decision a “victory for the wallets of every American consumer,” saying it ended “Trump’s illegal tariff tax” and “chaos” in trade policy. Major trading partners also responded cautiously. William Bain, head of trade policy at the British Chamber of Commerce, said the ruling clarified presidential powers but left uncertainty for businesses. Mexico’s President Claudia Sheinbaum said her administration was reviewing the decision, emphasizing the importance of maintaining trade agreements between the two countries. Trump’s announcement of a new 10% global tariff suggests his administration intends to continue aggressive trade policies despite the Supreme Court setback. Analysts say the ruling will have significant short-term implications for U.S. trade, including how previous tariff revenue might be refunded and whether global companies will adjust imports. The Supreme Court decision underscores the legal limits of executive power in U.S. trade policy. It clarifies that while the president can act in emergencies, major economic actions like global tariffs require explicit congressional authorization. As the Trump administration moves forward with alternative measures, the ruling will likely shape debates on executive authority and international trade for years to come.