The Prospects and Implications of Legal Challenges to President Trump’s IEEPA Tariffs

Since returning to office in January 2025, U.S. President Donald Trump has imposed far reaching tariffs on imports from every country in the world. Although he has continued to rely on legal authorities that he invoked during his first term, in particular section 232 of the Trade Expansion Act of 1962, Trump has broken new ground by relying on the International Emergency Economic Powers Act (IEEPA) of 1977 as the basis for his most sweeping actions. Over a dozen lawsuits have been filed in U.S. courts challenging the legality of these tariffs. Most were filed in April and May and thus challenge only the Liberation Day and fentanyl tariffs, although the resolution of those cases could have implications for other IEEPA-based tariffs. This policy brief explains these cases, including the legal claims raised, their current status, and the implications going forward should the challenges succeed.