The Supreme Court dealt a significant blow to President Donald Trump’s trade agenda Friday, ruling 6-3 that the administration overstepped its authority by using a 1977 emergency law to impose sweeping tariffs on foreign trading partners.
In a decision with major implications for executive power, Chief Justice John Roberts wrote for the majority that the International Emergency Economic Powers Act (IEEPA) does not grant the president authority to unilaterally impose tariffs of “unlimited amount, duration, and scope” — even after declaring a national emergency.
“The president asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope,” Roberts wrote. “In light of the breadth, history, and constitutional context of that asserted authority, he must identify clear congressional authorization to exercise it.”
Justice Clarence Thomas responded with a forceful dissent, arguing the court fundamentally misread both the statute and the Constitution’s separation of powers principles.
‘Mistaken’ Reasoning
Thomas, joined in part by Justices Samuel Alito and Brett Kavanaugh, contended that Congress had indeed provided clear authorization when it empowered the president to “regulate importation” under IEEPA.
“Throughout American history, the authority to ‘regulate importation’ has been understood to include the authority to impose duties on imports,” Thomas wrote.
The justice pointed to historical precedent, noting that President Richard Nixon’s 1971 import surcharge was upheld under IEEPA’s predecessor statute, the Trading with the Enemy Act. The U.S. Court of Customs and Patent Appeals affirmed that policy in 1975 under the same “regulate importation” language now at issue.
“The meaning of that phrase was beyond doubt by the time Congress enacted this statute, shortly after President Nixon’s highly publicized duties on imports were upheld based on identical language,” Thomas stated.
Nondelegation Doctrine
Thomas also took issue with the majority’s application of separation-of-powers principles, arguing the nondelegation doctrine — which forbids Congress from transferring core legislative power to the executive — does not apply to trade matters.
“As I suggested over a decade ago, the nondelegation doctrine does not apply to ‘a delegation of power to make rules governing private conduct in the area of foreign trade,’ including rules imposing duties on imports,” Thomas wrote. “Therefore, to the extent that the Court relies on ‘separation of powers principles’ to rule against the President is mistaken.”
Kavanaugh, in his own dissent joined by Thomas and Alito, emphasized that the court’s decision “cannot be justified as a matter of statutory interpretation.”
White House Response
President Trump, who had publicly urged the court to rule in his favor, held a press conference hours after the decision. He announced a new 10% global tariff while emphasizing that the “Supreme Court did not overrule tariffs” but “merely overruled a particular use of IEEPA
