It’s impossible to look away from President Donald Trump’s theatrical trade policy. Every day can bring a triumphant trade deal or a new tariff barrage. For markets and the news media, the minor detail of whether any of this is legal has faded into the background.
Why Trump’s tariffs are in trouble
The legality of Trump’s manic trade policies will be a question for the Supreme Court.
August 1, 2025 The Washington Post
Trump’s claim to virtually unlimited tariffing power comes from the 1977 International Emergency Economic Powers Act. The IEEPA is a sanctions and embargo law that doesn’t even mention tariffs. No president invoked it to impose tariffs for 48 years after its passage, until Trump did so this year. The Constitution says Congress, not the president, has the power to “lay and collect Taxes, Duties, Imposts and Excises,” and “regulate Commerce with foreign Nations.”
The U.S. Court of International Trade ruled 3-0 in May that Trump had exceeded his powers under the IEEPA, prompting the president to lash out with unusual ferocity. But the Federal Circuit suspended that ruling to let appeals play out, leaving Trump’s tariffs in effect, and the news media moved on.
Thursday’s argument suggests that the Federal Circuit’s “stay” decision wasn’t a judgment on the merits. The 11-judge panel seemed skeptical that the IEEPA is a strong enough legal basis for the president to commandeer Congress’s commercial and taxing powers.
Congress has written intricate trade laws over the past century that detail under what circumstances, at what levels and for how long the president can impose tariffs. “Why would the president ever rely on all of these trade statutes,” Judge Jimmie V. Reyna asked the Justice Department on Thursday, “if he has, under IEEPA, this unbounded power?” The judge added, “Your argument dislocates that entire U.S. trade-relief framework.”
Put more bluntly: If Trump is right, what is the point of U.S. trade law? The lawful tax rate on any import is just whatever the president says it is on any given day.
The Justice Department insisted that Trump’s tariff power is not unlimited. But conveniently, it also insisted that the key limit — whether there is, in fact, a national emergency triggering the IEEPA — is not reviewable by the courts. The only real check on unilateral presidential tariffs would therefore be new legislation explicitly stripping the president of the powers he usurped. But the president is “not likely to cabin his own authority by signing legislation,” Judge Timothy B. Dyk observed.
Eight of the 11 judges on the Federal Circuit panel were appointed by Democrats, including the two quoted above, so its eventual ruling won’t necessarily predict how the conservative-leaning Supreme Court will see the issue when the losing side appeals. But if the courts do eventually ratify the Trump administration’s position, it wouldn’t be an exaggeration to say that a key premise of the Constitution will have been inverted.
Legal-process arguments are sometimes the province of academics and pedants. Not this one. As one amicus brief notes: The Constitution assigned fiscal powers to Congress rather than the president “not as a formality, but as a structure of democratic accountability rooted in the issues that originally led to the creation of the United States.” The American colonies literally rebelled against Britain in part because it imposed tariffs without giving the colonists a say in Parliament.
Congress can delegate power to the president, of course. But one theme of this Supreme Court’s (conservative) jurisprudence in recent years is that when Congress delegates enormous powers, it must do so unambiguously. That “major questions doctrine” is designed to force accountability. The Supreme Court’s conservative majority has invoked it repeatedly against adventurous Democratic policies — voiding the Obama administration’s Clean Power Plan as well as the Biden administration’s orders barring evictions and forgiving student loans.
Did Congress really delegate all its constitutional power over border taxes a half-century ago in the IEEPA when it said presidents can “regulate … importation” during national emergencies? This delegation is at least as ambiguous as in past “major questions” cases. Yet Trump is exploiting the law to make further-reaching changes to the U.S. economy than did the Democratic policies that failed the major-questions test at the Supreme Court.
There appear to be three reasons so many smart people are nonetheless discounting the magnitude of the legal threat to Trump’s tariffs. The first is the perception that the Supreme Court favors executive power, and it’s true that Trump’s executive-power claims have been on a winning streak at the high court in recent weeks. But there is a profound difference between presidential power over the executive branch — the so-called unitary executive theory — and presidential power to reach into the other branches.
This court wants to protect core presidential powers, such as the power to remove subordinates, from interference. By the same token, it should want to carefully guard core congressional powers, such as the power to regulate commerce, from usurpation by the executive.
The second reason to downplay the threat to tariffs is the expectation that the Supreme Court will shy away from intervening in “foreign affairs.” Fair enough: The administration’s claims that an adverse ruling would disrupt diplomatic negotiations will probably carry some weight.
But though tariffs can be a tool of foreign affairs, they mechanically operate on U.S. companies within the borders of the United States, which must pay taxes on the products they import. President Harry S. Truman claimed foreign-affairs power to seize steel mills during the Korean War. The Supreme Court’s 1952 ruling blocking that seizure is one of the court’s most famous.
Republicans might want to be careful about carving out a zone of excessive deference to presidents who claim “foreign affairs” power to compel behavior by people and entities in the United States. Could a Democratic president impose Green New Deal policies and cite international climate diplomacy to win a pass from judges? What if the president claimed public health regulation was integral to national security and foreign affairs, since viruses cross borders?
The third reason some expect Trump’s tariffs to survive the Supreme Court is that the court’s conservative majority either favors Trump as a matter of partisanship or is cowed by his rhetoric and the specter that he will defy judicial orders. It’s certainly true that extralegal pressures affect the behavior of the Supreme Court, just as they affect any other institution.
But consider that a ruling against Trump on tariffs would be extraordinarily difficult to defy. Courts might not be able to force Trump to return a wrongly deported immigrant, for example, or to withdraw the National Guard from a city. But if the Supreme Court invalidated a border tax, Customs and Border Protection could not continue to passively collect it from thousands of well-lawyered U.S. corporations. Many would simply refuse to pay.
Moreover, if the Supreme Court is worried about its public standing, applying the major-questions doctrine against Republican as much as Democratic administrations might be the savvy long-term strategic move. Blessing Trump’s tariff policy after blocking comparatively minor Democratic power grabs would strengthen perceptions that the Supreme Court’s doctrines are applied asymmetrically, with unknown consequences the next time Democrats control the elected branches of government.
The bottom line is that Trump’s tariffs are on shaky legal ground. The administration is certainly preparing unilateral work-arounds in case of an adverse Supreme Court ruling. President Joe Biden tried other means of canceling student loans after the Supreme Court struck down his first attempt.
But if Trump’s trade deals are so great, why not insulate them from the courts by asking the GOP-controlled Congress to ratify them? The question answers itself: because Trump has no use for Congress. Which is precisely the legal and constitutional problem with his tariffs, and it isn’t going away.