In a landmark decision issued today, the Supreme Court ruled that President Trump's sweeping tariffs — imposed on imports from Canada, Mexico, China, targets based on late night truth social vibes, and virtually every other trading partner — were illegal.

The case, Learning Resources, Inc. v. Trump, No. 24-1287, asked a deceptively simple question: Does the International Emergency Economic Powers Act give the President the power to impose tariffs? Six justices said no.

What Happened

After taking office, President Trump declared national emergencies over illegal drug trafficking and trade deficits. Using those declarations as a legal foundation, he invoked IEEPA to impose a 25% duty on most Canadian and Mexican imports, duties on Chinese goods that eventually climbed to 145%, and a baseline "reciprocal" tariff of 10% or more on imports from nearly every country on earth.

Small businesses filed suit first. States followed. The cases eventually reached the Supreme Court on an expedited timeline. Yes. This was "fast" by SCOTUS standards.

What the Court Said

Writing for the majority, Chief Justice Roberts grounded the opinion in a basic structural principle: the Constitution gives the power to tax — and tariffs are taxes — to Congress, not the President. Article I, Section 8 is explicit on this point, and even the administration conceded that the President has no inherent tariff authority in peacetime.

The question, then, was whether Congress delegated that authority through IEEPA. The Court said it didn't.

IEEPA authorizes the President to "regulate" imports during a declared emergency. But the Court held that "regulate" does not mean "tax." Every other statute where Congress has granted tariff power uses specific language — words like "duty," "tariff," and "rate" — accompanied by caps, procedures, and guardrails. IEEPA has none of that.

The majority also invoked the major questions doctrine, which holds that Congress must speak clearly when delegating authority over issues of vast economic and political significance. The tariffs at issue here affected trillions of dollars in trade. No President in IEEPA's nearly 50-year history had ever used it this way. That kind of unprecedented, economy-shaking power requires more than an inference from a general statutory term.

The Dissent

Justice Kavanaugh, joined by Justices Thomas and Alito, disagreed. In their view, "regulate" naturally encompasses tariffs — they're just one form of import regulation. The dissent argued that IEEPA's broad language was intentional, that Congress meant to give the President sweeping emergency powers, and that the major questions doctrine shouldn't apply in the foreign affairs context where executive authority has traditionally been at its widest.

What It Means for Costco (and Everyone Else)

The immediate effect: every tariff imposed under IEEPA is now unlawful. Companies that have already filed suit seeking refunds — including Costco, Toyota, BYD, Goodyear, and Alcoa — are in a strong position to recover what they've paid.

So Can They Just Backfill With Other Statutes?

Technically, yes. Practically? Good luck.

The President still has tariff authority under Section 232 (national security) and Section 301 (unfair trade practices). These are real statutes with real teeth. But they come with something IEEPA apparently didn't require: actual work.

Section 301 tariffs have to be tethered to a specific investigation and specific findings. The Court of International Trade and the Federal Circuit have already made clear that even when China retaliated against initial Section 301 tariffs, the administration's response had to remain connected to the original investigation. To backfill what was lost today, the administration would need to launch fresh investigations, produce country-by-country findings of discriminatory trade practices, and set tariff levels proportional to the harm identified. Section 232 has a similar structure: the Commerce Department conducts an investigation that typically takes the better part of a year, issues a report, and the President's action has to be tied to the specific national security threat identified.

Could they do all of this? Sure. But it would take months — realistically years — to rebuild anything close to the scope of what the Court just struck down. And the result wouldn't look the same. These statutes are surgical instruments, not sledgehammers. You can't use a Section 301 finding about Chinese IP theft to blanket-tariff Canadian lumber and Mexican auto parts. You can't stretch a Section 232 national security finding on steel to cover every consumer good on a container ship. Each tariff has to be justified on its own terms, tied to its own record, and defensible in court.

That requires organization, focus, endurance, and serious legal and intellectual horsepower. This is not an administration known for any of those things. The IEEPA tariffs were attractive precisely because they required none of that — just an emergency declaration and a posting schedule that seemed to correlate more closely with the President's mood than with any coherent trade strategy. The era of governing trade policy by late-night Truth Social rant is over.

If the administration wants sweeping tariffs back, it needs Congress to pass legislation. Given the current political dynamics, that's far from guaranteed. In the meantime, the days of waking up to find out your supply chain costs changed 45% overnight because someone was doomscrolling at Mar-a-Lago are done.

The opinion is Learning Resources, Inc. v. Trump, No. 24-1287 (U.S. Feb. 20, 2026).

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