• Chief Justice Roberts says tariffs are direct exercise of congressional authority
• Other justices grill defence, citing concerns about Congress’s constitutional role, the intent behind emergency law and its interpretation

WASHINGTON: US Supreme Court justices from across the ideological spectrum on Wednesday questioned the legality of President Donald Trump’s sweeping tariffs, hearing a landmark case that could uphold or upend a key pillar of his economic agenda and test the limits of presidential power.

In a contentious session, justices pressed the Trump administration’s lawyer on whether the president had intruded on the power of Congress by citing emergency powers to impose tariffs on nearly every US trade partner.

At stake are billions of dollars in customs revenue, a key lever in Trump’s trade wars, and a fundamental debate over the separation of powers.

The court’s nine justices are considering Trump’s use of the International Emergency Economic Powers Act (IEEPA), a 1977 law allowing a president to regulate commerce during a national emergency.

A lower court ruled in May that Trump had exceeded his authority by using the law to impose broad tariffs, prompting the administration’s appeal.

The solicitor general arguing for the administration, D John Sauer, faced immediate scepticism from both conservative and liberal justices over the government’s interpretation of the law and the vast economic consequences of the tariffs.

A central issue before the court is whether the “major questions doctrine” applies. The doctrine requires clear and explicit authorisation from Congress for executive branch actions with vast economic and political significance.

Chief Justice John Roberts challenged Mr Sauer on why the doctrine would not apply to tariffs of such immense scale.

“The justification is being used for a power to impose tariffs on any product, from any country, in any amount, for any length of time,” Justice Roberts said. “I’m not suggesting it’s not there, but it does seem like that’s major authority, and the basis for that claim seems to be a misfit. So why doesn’t it apply?”

Mr Sauer argued the doctrine does not apply in the context of foreign affairs, where presidents have broad authority. He contended that the issue was not the tax but rather to regulate foreign commerce, calling the imposition of tariffs a “core application” of such authorities.

Roberts pushed back, framing the tariffs as a direct exercise of congressional authority. Liberal justices echoed these concerns. Justice Elena Kagan noted that the power to impose taxes and regulate foreign commerce are usually considered “quintessential” powers belonging to Congress, not the president.

Justice Ketanji Brown Jackson added that IEEPA was intended to limit, not expand, presidential authority.

Conservative justices also raised pointed questions. Justice Amy Coney Barrett asked Sauer if he could cite any other instance where the phrase “regulate importation” was used to grant the power to impose tariffs.

Justice Neil Gorsuch warned that the administration’s broad interpretation of presidential power threatened the constitutional separation of powers, suggesting it could become a “one-way ratchet toward the gradual but continual accretion of power in the executive branch and away from the people’s elected representatives”.

The administration, however, did find some potential support. Justice Brett Kavanaugh noted a possible precedent, pointing out that former President Richard Nixon had imposed a worldwide tariff in the 1970s under a predecessor statute to IEEPA that contained similar language.

Trump considered attending the hearing but decided against it, stating he did “not want to distract” from the proceedings. However, Treasury Secretary Scott Bessent and US Trade Representative Jamieson Greer were present.

Published in Dawn, November 6th, 2025