The Trump Section 301 tariffs landed on Friday and drew a courtroom challenge within hours, setting up a fight that may determine whether the president can rebuild a trade agenda the Supreme Court already dismantled once.

The administration imposed sweeping duties on goods arriving from more than 80 countries, arguing those nations have failed to meaningfully stamp out forced labor in their supply chains. The scope is enormous. The affected trading partners account for 99.4% of all U.S. trade, meaning almost nothing entering the country escapes the new regime.

A Familiar Law Used in an Unfamiliar Way

The duties rest on Section 301 of the Trade Act of 1974, a provision that allows the government to hit imports with levies when a foreign country engages in unfair trade practices.

That statute is not obscure. Presidents from both parties have reached for it over the decades, and Trump himself used it against China during his first term. What has trade lawyers uneasy is not the tool but how far it is being stretched.

Peter Harrell, a visiting scholar at Georgetown University Law Center’s Institute of International Economic Law, said the president is applying the law in a fundamentally different manner than anyone before him. In his reading, Congress never designed Section 301 to let a president rewrite the entire tariff schedule at once or impose duties with no expiration. He believes the courts could absolutely strike this version down.

Trump, for his part, appears to view the provision as his main runway for future action. On the same day the tariffs took effect, he announced the United States would immediately open a Section 301 investigation into the European Union, framing it as payback for the substantial fines Brussels has levied against American technology companies.

That came amid a burst of trade activity. In recent days he has also placed 25% duties on Brazilian goods — again through Section 301 — and threatened 50% tariffs on certain Canadian products.

The Lawsuit Arrives Almost Immediately

Two small businesses filed suit in the U.S. Court of International Trade barely hours after the tariffs went live. Their central claim is that the forced-labor rationale is cover, and that the administration is quietly reassembling the same global tariff structure the Supreme Court rejected five months earlier.

The timing sits at the heart of their argument. The new duties took effect precisely as an earlier round of tariffs expired. Those lapsed measures had been announced under Section 122 of the same 1974 law, rolled out within hours of the Supreme Court’s February 20 decision. Because Section 122 carries a built-in time limit, they were always going to run out.

That February ruling was the decisive blow to the original plan. The justices concluded that the International Emergency Economic Powers Act, the authority Trump used to impose duties on nearly every nation on earth, simply did not grant him that power.

Friday’s complaint argues the replacement is engineered to preserve substantially the same broad system that both the trade court and the Supreme Court found Congress had never authorized. Section 301, the filing contends, is not an open-ended license to tax nearly all imports from nearly all partners at rates chosen to mirror the invalidated program rather than to actually address any identified foreign conduct.

The case was brought by the Liberty Justice Center, the same legal nonprofit that represented the winning plaintiffs in the IEEPA challenge. The organization’s position is blunt: an administration cannot rescue a predetermined global tariff policy by shopping from one statute to another.

The Administration’s Defense

Officials reject the idea that this is a workaround.

A senior administration official told reporters on a call ahead of the announcement that combating forced labor has been a genuine priority of the president for many years. Asked why the tariffs arrived exactly as the previous batch lapsed, the official offered a procedural explanation, saying the timing was chosen to avoid complexity.

A spokesperson for the Office of the U.S. Trade Representative did not immediately respond to a request for comment on the lawsuit.

Where the Experts Land

Opinion among trade specialists is split, though skepticism dominates.

Kimberly Clausing, a tax law professor at UCLA and senior fellow at the Peterson Institute for International Economics, said flatly that she considers the measures clearly unlawful. She argued the tariffs go well past what the statute was written to accomplish and described the forced-labor framing as pretext for reviving the IEEPA regime. In her view, nothing connects a blanket tariff of this kind to the stated goal of curbing forced labor. She also cautioned that no one can predict judicial outcomes with confidence, and that any challenge will take considerable time to work through the system.

Alan Wolff, also a senior fellow at the institute, wrote that he expects the Supreme Court to reject the forced-labor duties. His reasoning turns on a threshold requirement in the law: to trigger Section 301’s retaliatory power, a country’s conduct must be shown to burden American commerce. He does not see that showing made for the roughly 60 targeted nations, which together represent nearly all U.S. imports and about 90% of global trade.

Not everyone agrees the case is a loser for the government. Greta Peisch, a former general counsel at the U.S. Trade Representative’s office and now a partner at Wiley Rein, noted that the administration appears to have followed the procedural steps the statute requires. She described the law’s text as offering considerable latitude, making it a difficult standard for challengers to overcome.

Andrew Siciliano, who leads trade and customs work globally and in the U.S. for KPMG, made a similar point from a practical angle. Because Section 301 has such a long history of use, he suggested the new duties may prove harder to unwind than their predecessors.

What Businesses Should Do Now

Siciliano’s advice to companies was direct. Rather than betting on a quick reversal, firms should build their plans around the tariffs currently in force.

That guidance reflects the reality of litigation timelines. Even a challenge that eventually succeeds can take many months to resolve, and importers will pay the duties throughout. For businesses managing thin margins and fixed contracts, the legal merits matter far less in the short term than the invoices arriving now.

The broader question remains open. If courts accept that a president may swap statutes to reach the same outcome, the practical limits on unilateral tariff power shrink considerably. If they refuse, the administration will be searching for a fourth legal foundation — and running out of options.