The case centres on tariffs imposed by Trump in April last year on imports from multiple countries, including Canada, Mexico and China. The duties ranged from 10% to as high as 50% and were justified by the Trump administration on grounds of national security, citing issues such as fentanyl trafficking and economic dependence on foreign nations.
At the heart of the dispute is whether Trump exceeded his legal authority by invoking the International Emergency Economic Powers Act (IEEPA) of 1977 to impose country-specific import tariffs. The law grants the president broad powers to regulate foreign economic transactions during a declared national emergency but does not explicitly reference tariffs.
Trump has repeatedly defended the measures, claiming the tariffs generated more than $600 billion in revenue and helped strengthen domestic manufacturing while reducing reliance on imports. He framed the trade deficit as a national emergency, arguing that aggressive tariffs were necessary to protect US economic and security interests.
The legality of that argument has been challenged by a coalition of 12 US states—Arizona, Colorado, Connecticut, Delaware, Illinois, Maine, Minnesota, Nevada, New Mexico, New York, Oregon and Vermont—along with several small businesses. The plaintiffs contend that the president overstepped constitutional and statutory limits by unilaterally imposing import taxes without congressional approval.
The Supreme Court has already expressed reservations about the breadth of the claimed authority. During hearings held last November, justices questioned whether the IEEPA could be interpreted to permit global tariffs, noting that the statute does not mention tariffs and lacks clear boundaries on executive power. In an earlier interim ruling, the court allowed the administration to impose tariffs of up to 15% for a limited period of 150 days, provided sufficient justification was offered.
Legal experts say the eventual ruling could have far-reaching implications, not only for US trade policy but also for the balance of power between the executive branch and Congress. A decision limiting the use of emergency powers could constrain future presidents, while a broad endorsement could significantly expand executive authority in economic matters.
For now, the uncertainty continues, with businesses, states and global trading partners awaiting clarity on whether the tariffs will ultimately stand or be struck down.
