Today, in a 6-3 decision, the Supreme Court struck down President Trump’s sweeping and unilaterally imposed tariffs, correctly holding that the International Emergency Economic Powers Act (IEEPA) does not authorize presidents to impose tariffs. The Constitution gives that power to Congress, not the president, and nothing in IEEPA’s text or history indicates that Congress meant to hand over this fundamental power.

The Court’s opinion draws on arguments we advanced in our amicus brief. A central part of President Trump’s defense of the tariffs, echoed by the principal dissent, was a flawed and convoluted historical narrative—that nineteenth-century presidents imposed wartime tariffs, that this authority was codified in a predecessor statute to IEEPA and retained through various revisions over the years, and that this authority was transmitted to IEEPA in 1977.

Our brief dismantled this narrative, and the Court’s opinion tracks that analysis closely in rejecting the administration’s claims. As the Court explained, the supposed path from “wartime precedents, through multiple iterations” of IEEPA’s predecessor statute, to IEEPA itself, relied on an “attenuated chain” of inferences that “cannot support” President Trump’s claimed power to impose tariffs.

The Constitution’s allocation of the taxing power to Congress is no relic: it is a structural safeguard put in place by the Framers. Today’s decision vindicates that design by confirming that Congress did not surrender this fundamental power in a statute that was designed to limit, not expand, the president’s emergency authority.