The decision is the biggest defeat the second Trump administration has faced in U.S. courts. Last year the court repeatedly sided with the president in a series of emergency “shadow docked” rulings involving immigration, the removal of heads of independent agencies, and encroachments on congressional authority to allocate federal funding.
In the majority opinion of the 6–3 ruling, Chief Justice Roberts wrote that the 1977 International Emergency Economic Powers Act, which gives the president authority to regulate or prohibit certain international transactions during a national emergency, does not authorize broad, indiscriminate tariffs.
“The president asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope,” the opinion reads.
“In light of the breadth, history, and constitutional context of that asserted authority, he must identify clear congressional authorization to exercise it.”
The ruling concerns broad import tariffs Trump imposed beginning in April 2025. Trump called the tariffs “reciprocal” and applied them against virtually all countries. Justices Kavanugh, Alito, and Thomas dissented.
The federal government will now have to find a mechanism to reimburse everyone who paid extra under the illegal tariffs. According to CNN, this amounts to $134 billion in government revenue.
“The issue of refunds has loomed large over the case, with Trump administration officials saying that potential repayments could have devastating consequences for the U.S. economy,” the report said.
“That question will likely need to be sorted out by lower
courts.”