In a 6–3 decision, the Supreme Court held that President Donald Trump overstepped his authority by using the International Emergency Economic Powers Act (IEEPA) to impose sweeping tariffs on nearly all major trading partners, including broad “reciprocal” duties tied to perceived unfair practices and separate measures aimed at Mexico, Canada, and China over drugs and migration.

The majority opinion, authored by Chief Justice John Roberts, found that IEEPA allows regulation of imports in emergencies but does not grant the distinct, constitutionally sensitive power to tax or impose tariffs, which the Court stressed belongs to Congress.