The U.S. Supreme Court has struck down President Donald Trump’s sweeping global tariff regime, ruling that he overstepped his authority by using emergency powers to impose levies on nearly every American trading partner.
In a decision released Friday, the court found that Trump’s reliance on the 1977 International Emergency Economic Powers Act (IEEPA) to justify broad-based tariffs was unconstitutional, concluding that the law does not grant the president authority to unilaterally restructure global trade without congressional approval.
The 6-3 ruling invalidates the legal foundation for the tariffs that have been in place for much of the past year and could force the U.S. Treasury to refund billions of dollars collected from importers.
Trump had argued that the tariffs were necessary to address economic threats and boost domestic manufacturing, declaring a national emergency under IEEPA in order to bypass Congress. The administration imposed duties on goods from countries including Canada, Mexico, China and members of the European Union.
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Last August, a U.S. appeals court ruled that most of the tariffs were illegal but allowed them to remain in effect pending further review. The Supreme Court took up the case after the White House asked it to overturn that decision.
In its ruling, the high court said the Constitution vests the power to regulate foreign commerce in Congress and that while presidents have some latitude in responding to genuine national emergencies, IEEPA does not provide “boundless authority” to impose tariffs of this scope and duration.
The decision marks a major blow to Trump’s economic and foreign policy strategy during his second term. The tariffs had been a central tool in negotiations with key trading partners and a cornerstone of his effort to reshape global supply chains.
The ruling will be welcomed in Canada, which has been subject to multiple rounds of U.S. duties under the emergency powers framework. Canadian officials have long argued that the tariffs were unlawful and economically damaging.
But this ruling does not automatically eliminate all U.S. tariffs affecting Canada. Ottawa has been subject to a separate 35 per cent tariff regime imposed under what the White House described as a “fentanyl-related” national emergency, which rests on a different legal footing.
While Friday’s decision strikes down the broad global tariffs imposed under the 1977 International Emergency Economic Powers Act, legal experts have said the status of the Canada-specific measures will depend on how closely they are tied to the same statutory authority and emergency declaration.
Canadian officials have previously argued that the fentanyl-linked tariffs are politically motivated and economically unjustified. The Supreme Court’s ruling is likely to intensify scrutiny of any remaining duties that rely on similar emergency powers.
Legal analysts say today's decision could also have significant financial implications, as importers may seek refunds for duties paid over the past year. It also reasserts congressional authority over trade policy at a time of heightened geopolitical and economic tensions.
The White House did not immediately indicate how it would respond to the ruling.
In its majority opinion, the court said the Constitution gives Congress — not the president — authority over tariffs and foreign commerce.
“The Constitution assigns to Congress the power to lay and collect Duties, Imposts and Excises, and to regulate Commerce with foreign Nations,” the ruling states.
Chief Justice John Roberts wrote that while the 1977 International Emergency Economic Powers Act grants the president significant authority during national emergencies, it “does not grant the President unbounded authority to impose tariffs on imports from any country, of any product, at any rate, for any duration.”
“The Government’s reading would effectively transfer to the President the core legislative power over tariffs,” the opinion says.
In a concurring opinion, Justice Neil Gorsuch warned that even a broader reading of the statute would raise constitutional red flags. “Even if the statute were read to permit the measures challenged here, serious constitutional questions would arise,” he wrote, adding that “the power to tax and to set tariffs lies at the heart of the legislative function.”
In dissent, Justice Brett Kavanaugh said the majority had gone too far in limiting executive authority. “The Court unduly constrains the Executive’s ability to respond swiftly and effectively to international economic threats,” he wrote, arguing that Congress had drafted the law in “expansive terms” and that the president acted within the authority it conferred.
The ruling was issued in a 6-3 decision, with Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito, Neil Gorsuch, Amy Coney Barrett and Ketanji Brown Jackson in the majority, while Justices Sonia Sotomayor, Elena Kagan and Brett Kavanaugh dissented.
