Landmark IEEPA Case Challenges Presidential Power to Impose Broad Tariffs

The U.S. Supreme Court will hold oral arguments on November 5 in a landmark case testing President Donald Trump's authority to impose sweeping tariffs under the 1977 International Emergency Economic Powers Act (IEEPA), according to a Bloomberg report. If Trump attends the hearing in person, he would become the first sitting president in the court's 235-year history to witness arguments at the nation's highest tribunal, noted a Japan Times piece. The case, which has drawn over 40 amicus briefs from diverse stakeholders, could redefine the balance of power between the executive and legislative branches and reshape U.S. trade policy for decades, according to a CBC News analysis.

At issue is whether Trump's use of IEEPA to justify tariffs—ranging from 10% to 50% on imports from nearly all trading partners—exceeds his statutory authority, according to a Brennan Center analysis. Lower courts have already ruled against the tariffs, with the Federal Circuit's 7-4 decision asserting that IEEPA does not grant presidents the power to impose broad import duties, as reported in an Invezz report. The appeals court applied the "major questions doctrine," a principle holding that Congress must clearly authorize policies of vast economic significance, in a ruling discussed by an ABC News analysis. Trump's administration argues that the term "regulate importation" in IEEPA encompasses tariffs and that courts should defer to executive judgments on national security, according to a GMF analysis.

The stakes are monumental. The IEEPA tariffs have generated $89 billion in revenue through September 2025, offsetting parts of the federal deficit and funding initiatives like port fees for China-linked ships, according to a Reuters report. If struck down, the government could face unprecedented challenges refunding over $100 billion in collected duties, a process that experts warn could take years and impose financial burdens on both importers and taxpayers, the report found. For Trump, a loss would jeopardize his signature trade agenda, which he has framed as essential to protecting American jobs and national security, analysts writing in Invezz warned.

Legal scholars and advocacy groups have raised constitutional concerns, noting that Article I of the Constitution grants Congress the power to "lay and collect duties," a authority it has historically delegated to the executive under specific conditions, ABC News notes. The Brennan Center for Justice argues that allowing IEEPA to authorize tariffs would create an "unconstitutional delegation" of legislative power, eroding checks on presidential authority, while the Trump administration warns that invalidating the tariffs would weaken the U.S. position in global trade negotiations and embolden adversaries.

Trump's potential attendance at the hearing adds symbolic weight to the proceedings. While past presidents have addressed the court during ceremonial events or as lawyers, none have observed oral arguments, the Japan Times observed. His presence, if realized, would underscore the personal stakes of the case and signal the administration's confidence—or desperation—in the face of judicial scrutiny. The court's decision, expected by year-end, will determine whether the president's tariff strategy survives or collapses under the weight of legal and constitutional challenges.