Major Questions, Nondelegation, and the Section 338 Tariffs Against Canada

I have previously written about Trump’s harmful and illegal imposition of Section 338 tariffs against various Canadian imports, and his recent expansion of those actions to include categorical bans on some Canadian products. In this post, I will explain how the legal case against these actions is bolstered by the major questions and nondelegation doctrines.

Section 338 was part of the infamous Smoot-Hawley tariff act of 1930, which gravely exacerbated the Great Depression. There is a strong case that Trump’s Section 338 tariffs are illegal both because Section 338 (which has never been used previously) was superseded by later legislation, and because Trump’s tariffs do not meet the textual requirements of Section 338. On the former point, see this 2025 Volokh Conspiracy guest post by Philip Zelikow of the conservative Hoover Institution. On the latter, see this excellent guest post by Georgetown University trade policy experts Peter Harrell and Jennifer Hillman.

But assume it is unclear whether Section 338 has been superseded and whether the Trump tariffs on Canadian imports meet the requirements emphasized by Harrell and Hillman: that Section 338 tariffs must be in response to foreign trade polices that “discriminate” against US goods, and must “offset” those discriminatory policies. In that event, the major questions doctrine (MQD) weighs against Trump’s position.

MQD requires Congress to “speak clearly” when authorizing the executive to make decisions of “vast economic and political significance.” It played a major role in litigation against Trump’s massive International Emergency Economic Powers Act (IEEPA) tariffs. Bot the US Court of Appeals for the Federal Circuit (which has jurisdiction over all US tariff cases), and three Supreme Court justices struck down those tariffs in large part based on MQD.

Under the administration’s interpretation of Section 338, it can be used to impose virtually unlimited tariffs against goods from almost any trading partner, so long as that government imposes any restrictions at all on American imports. They would not have to be meaningfully discriminatory, and the Section 338 tariffs would not have to be “offsetting” in the sense of closely calibrated to the trading-partner restrictions they are supposed to be countering. That kind of sweeping discretion over tariffs creates an obvious major question, inasmuch as it gives the president vast power over the US and world economies. And that power would not be limited to just US-Canada trade, though even the latter is extremely important, given that Canada is one of our biggest trading partners and the two economies are closely intertwined in many ways.

Trump’s recent expansion of Section 338 restrictions further accentuates the “major” nature of the issues at stake. He has now used Section 338 to ban some imports entirely, as opposed to “merely” imposing tariffs. Under the administration’s interpretation of Section 338, the power to embargo goods would also be nearly unlimited, so long as the trading partner in question imposes at least some constraints on US imports, and doesn’t lift them in response to initial Section 338 actions. And, as the analyses by Zelikow and Harrell and Hillman show, it is at the very least far from clear that Section 338 is still in force, and that it gives Trump the sweeping power he claims.

If courts conclude that Section 338 does somehow authorize Trump’s actions, even in spite of MQD, they should strike it down under the nondelegation doctrine, which limits  delegation of legislative power to the executive. As the Supreme Court emphasized in the IEEPA case, tariffs are a congressional power, not an executive one. Thus, they are, subject to nondelegation restrictions. The power to ban imports entirely is also a congressional power, part of the authority to regulate international commerce.

The Supreme Court’s nondelegation precedent is far from a model of clarity. But last year’s decision in FCC v. Consumers’ Research held that delegations of the power to impose taxes (including, presumably, tariffs) must have a clear floor and ceiling and that “[t]he guidance needed is greater when an agency action will affect the entire national economy than when it addresses a narrow, technical issue.” There is no meaningful floor or ceiling to Trump’s interpretation of Section 338. And the authority claimed by the administration is obviously one that affects the “entire national economy.”

As the Supreme Court emphasized in the IEEPA case, the president is not supposed to have the power to “impose tariffs on imports from any country, of any product, at any rate, for any amount of time.” Trump’s approach to Section 338 would give him exactly that. Since the Supreme Court issued that decision, Trump has repeatedly tried to use other legislation to achieve the same sweeping power: Section 122 of the Trade Act of 1974 (invalidated by the US Court of International Trade, though the case is on appeal), Section 301 of that same act (the issue is now being litigated), and now Section 338. Courts should continue to reject these power grabs.

So far, there have not been any cases filed challenging the Section 338 tariffs. I hope that will soon change. And, when it does, the plaintiffs should make sure to make major questions and nondelegation arguments, in addition to other points.