The U.S. Supreme Court heard arguments Wednesday in a major challenge to President Donald Trump’s global tariff program, a case that could reshape the balance of power between the White House and Congress on trade and economic policy.
The dispute centers on Trump’s use of the International Emergency Economic Powers Act of 1977 (IEEPA) to levy sweeping tariffs on imports from dozens of countries. Under the policy, Chinese goods faced duties as high as 145 percent, while products from Canada and Mexico saw 25–35 percent tariffs. Most other countries faced at least 10 percent. The administration said the tariffs were justified as part of national emergency declarations tied to trade deficits and issues such as fentanyl trafficking.
Opponents — including small businesses, importers, and several Democratic-led states — argued that IEEPA does not grant tariff authority. They contend tariffs function as taxes, a power assigned to Congress under the Constitution. They also said the law was designed for targeted sanctions against hostile nations, and does not authorize imposing broad economic pressure on allies.
Three lower courts have ruled against the administration’s use of IEEPA in this context, but allowed the tariffs to remain in place while appeals continue. If the nation’s highest court ultimately strikes them down, it could require the government to return $90 billion to $195 billion in tariff revenue.
During more than two hours of questioning, justices across the ideological spectrum signaled skepticism toward the administration’s interpretation of IEEPA. Members of the Court’s conservative majority pressed the government on whether the statute could effectively give the president open-ended authority to impose tariffs whenever a national emergency is declared, regardless of whether Congress has acted. The concern was that such a reading would allow any future administration to impose broad trade duties on virtually any product from any country, without further congressional approval.
Justice Amy Coney Barrett questioned the lack of historical precedent for using IEEPA to impose tariffs of this scale, noting that the statute has historically been associated with targeted sanctions, not sweeping trade programs. Her questions also acknowledged the “mess” that could result if the tariffs are struck down, since the ruling could require mass refunds to importers.
Chief Justice John Roberts focused on the administration’s claims of presidential authority, raising the possibility that IEEPA’s language may not align with such far-reaching economic actions, suggesting the statute may be a “misfit” for the role the government has assigned to it.
On the other end of the bench, the Court’s liberal justices emphasized that IEEPA was enacted to limit unilateral executive power, not to expand it into routine trade issues such as global supply chain competition or tariff rate negotiations. They pointed to the major questions doctrine, suggesting that actions of this magnitude require explicit authorization from Congress.
Justice Brett Kavanaugh concentrated on earlier precedents involving presidential tariff authority during the Nixon era, asking why Congress did not expressly prohibit similar measures when drafting IEEPA, a line of questioning that made him the least predictable vote.
Dozens of amicus briefs have been filed in the case, with the majority opposing the tariffs. Economists, national security specialists, lawmakers, and industry organizations warned that endorsing the administration’s approach could weaken congressional control over trade and establish a broad precedent for unilateral executive action.
The administration argued that overturning the tariffs could have serious economic and diplomatic consequences, while challengers said any refund process would follow existing U.S. customs procedures, even if administratively complex.
The case was fast-tracked and heard on an accelerated schedule. A ruling is expected to be issued more quickly than usual, given the substantial financial stakes.
