Federal Courts Rule Against Trump's Tariff Authority: A Constitutional Challenge to Presidential Trade Powers A landmark legal battle has emerged challenging the constitutional limits of presidential tariff authority, with federal courts delivering decisive rulings against President Donald Trump's sweeping use of emergency powers to impose tariffs. The U.S. Court of International Trade unanimously ruled on May 28, 2025 that Trump exceeded his constitutional authority by using the International Emergency Economic Powers Act (IEEPA) to impose broad tariffs on imports from dozens of countries. The Constitutional Foundation: Congress Controls Tariffs The legal challenge rests on a fundamental constitutional principle: Article I, Section 8 of the Constitution explicitly grants Congress the power "to lay and collect taxes, duties, imposts, and excises". This provision makes clear that tariff authority belongs exclusively to the legislative branch, not the executive . Th...