Supreme Court strikes down bulk of Trump's tariffs

Roberts said the tariffs violated the major questions doctrine. Trump's interpretation of the 1977 International Emergency Economic Powers Act would be an "expansion of the President's authority over tariff policy" that Congress didn't intend.

"There is no exception to the major questions doctrine for emergency statutes," the majority wrote. "Nor does the fact that tariffs implicate foreign affairs render he doctrine inapplicable. The Framers gave 'Congress alone' the power to impose tariffs during peacetime."

Twelve states, five small businesses and two Illinois-based toymakers have challenged Trump's authority to impose tariffs under the 1977 law without Congressional approval.That law, the International Emergency Economic Powers Act, does not mention the word "tariff" and, as the challengers stress, has never been used to impose tariffs.s.

The Supreme Court noted that in Friday's decision.

"It is also telling that in IEEPA’s half century of existence, no President has invoked the statute to impose any tariffs, let alone tariffs of this magnitude and scope," the high court wrote.

In November, Trump's legal team had argued that the law is a clear delegation of emergency power, granting the president broad authority to act in times of crisis.

In August, the U.S. Court of Appeals for the Federal Circuit affirmed a lower court's ruling that Trump did not have the authority, but said Trump's tariffs could remain in place while the administration appeals to the U.S. Supreme Court. In the 7-4 decision, the Federal Circuit majority held that tariff authority rests with Congress.