USTR Jamieson Greer announced Wednesday that the Trump administration is launching investigations under Section 301 of the Trade Act of 1974, targeting China, the EU, Mexico, and more than a dozen other countries over what the administration calls "structural excess capacity."
Fortune reported that the move represents a strategic shift to firmer legal ground after the Supreme Court struck down the administration's sweeping tariffs implemented under the International Emergency Economic Powers Act of 1977.
The pivot matters. Section 301 isn't some untested executive gambit. It's a statute that has survived legal challenge after legal challenge, including approximately 3,600 importers contesting 25% tariffs on hundreds of billions of dollars' worth of Chinese-origin goods at the Court of International Trade in 2023 alone. Even Biden used it.
The reason this story deserves attention isn't just the scale of the probes. It's the legal architecture underneath them. Section 301 is an agency action, meaning the acting USTR must follow guidelines under the Administrative Procedure Act, including providing a public comment period. That procedural framework is precisely what makes the law so resilient in court.
Timothy Meyer, an international trade expert and Duke Law School professor, put it plainly:
"For the plaintiffs, challenging whatever the administration does here is going to be much more difficult than the IEEPA case."
That's a significant concession from an academic observer. The IEEPA tariffs were vulnerable because the statute wasn't designed for broad trade policy. Section 301, by contrast, was built for exactly this purpose: investigating and responding to unfair trade practices by foreign governments.
The law has weathered more than 130 associated cases. It is, in the plainest terms, battle-tested.
Meyer added a note of caution about execution:
"I think the administration, if it does the investigation well, is going to have a reasonably good litigating position here. But a lot depends on what the administration does."
In other words, the legal tool is sound. The question is how carefully the administration wields it.
Here's the part that makes Democratic opposition to these probes particularly awkward. Biden in 2024, during the four-year periodic review required under the law, extended the tariffs on China and even increased them on products like electric vehicles and medical materials.
He didn't just maintain the Section 301 framework Trump built during his first term. He expanded it.
That makes any forthcoming progressive outrage over Section 301 probes ring hollow. The legal pathway was good enough for Biden when he wanted to look tough on Chinese EVs heading into an election year.
It doesn't suddenly become authoritarian overreach because a different administration is using the same statute more ambitiously.
The left's objection was never about the law. It was always about who holds the pen.
Since the start of Trump's second term, U.S. importers have navigated a series of back-and-forth tariff implementations and reversals. The uncertainty has been real, and the business community is paying close attention to what these new probes mean for planning and cost structures.
Blake Harden, a managing director in Washington, D.C. who helps run EY's global trade policy practice, described the mood among importers:
"They're trying to understand how quickly this could potentially go. They're trying to understand if this is something that they should comment on."
These investigations can legally take up to a year, which introduces a different kind of timeline than the IEEPA tariffs that could be implemented rapidly. That slower pace could actually benefit businesses by providing more predictability, even if the eventual tariff rates end up being significant.
Harden also flagged concern about "double-scope" between Section 232 and Section 301 investigations, where some sectors already under one investigation could face overlapping scrutiny. And she raised a more interesting question about how these probes affect ongoing trade negotiations:
"'What does this mean for the trade deal with country X?' How is that going to potentially accelerate the discussions and negotiations or potentially cause those to perhaps go off the rails or to be paused?"
That dual dynamic, where investigations serve as both enforcement mechanism and negotiating leverage, is central to understanding the strategy at work.
The timing adds another layer. Current short-term 10% tariffs enforced under Section 122 of the 1974 Trade Act are set to expire by the end of July. The Section 301 probes serve as the next wave, a more legally durable replacement for the tools the courts have narrowed or the calendar will eliminate.
Think of it as layered trade architecture. The administration isn't relying on a single legal authority anymore. It's building redundancy across multiple statutes, each with its own procedural requirements, timelines, and judicial track records. If one pillar gets knocked out, the others remain standing.
That's not chaos. That's adaptation.
The fundamental difference between the IEEPA tariffs and the Section 301 approach is procedural legitimacy. IEEPA was designed for genuine national emergencies, and courts were always going to scrutinize its application to routine trade policy.
Section 301, on the other hand, exists specifically so the executive branch can investigate and penalize unfair foreign trade practices. The statute anticipated this exact use case.
The public comment period, the investigation timeline, the agency action framework: all of it creates a record that courts are far more likely to defer to. Opponents will still file lawsuits. They always do. But the legal terrain has shifted dramatically underneath them.
Three thousand six hundred importers challenged the first round of Section 301 tariffs on China. The tariffs survived. Biden kept them. Then he raised them.
The administration just picked the one tool its opponents have already proven they can't break.
