When the Supreme Court hears arguments next week on President Donald Trump’s tariffs, prepare for crossed wires. Liberals who typically oppose Trump’s economic policies will espouse traditionally conservative legal principles. Conservatives who prioritize doctrine over Trumpism will agree with those liberals, forming an unlikely alliance. And those who reflexively support anything Trump does, for the pure Trump of it all, will twist themselves into pretzels to justify the President’s unbounded executive power grab. In the end, the Court is likely (though not certain) to strike down Trump’s tariff plan, as presently constituted.

The legal battle began in the Court of International Trade, a federal court that handles disputes over international commerce. In May, a panel of three judges – appointed to the bench by Presidents Ronald Reagan, Barack Obama, and Trump himself – unanimously found invalid the tariffs implemented on the President’s first day in office against Mexico, Canada, and China, as well as the worldwide tariffs announced on the Trump-branded “Liberation Day,” April 2, 2025. Immediately after the loss, Trump lashed out against the Federalist Society (which has recommended many of his judicial nominees) and its founder, Leonard Leo (a “sleazebag” and a “bad person”).

In August, a federal court of appeals reached the same conclusion, finding the tariffs unconstitutional by a seven-to-four vote. (Unlike other federal appeals courts, which typically use three-judge panels, the international trade court issues rulings from its entire roster of active judges.) The seven judges in the majority were appointed by Presidents George H. W. Bush, Bill Clinton, Obama (three judges), and Joe Biden (two judges). The four dissenters included two George W. Bush nominees and two Obama nominees. (Trump has not appointed any judges to this court.) Notwithstanding the cross-ideological composition of both sides of the outcome, Trump blasted the “Highly Partisan Appeals Court” that ruled against him. 

The crucial point, moving forward, is that the court of appeals ruling turned largely on a legal concept known as the “major questions” doctrine. In short, the court explained, if Congress intends to delegate authority to the president to make decisions of “vast economic and political significance” (“major questions”) then it must provide “clear Congressional authorization” through a statute.  

As the appeals court noted, Congress unquestionably holds the tariff power in the first place under Article I of the Constitution – and it can choose to give some of that power to the Executive Branch, by passing a law. However there’s nothing in the law cited by Trump – the International Emergency Economic Powers Act of 1977 (“IEEPA”), which allows the President to regulate foreign commerce to protect against any “unusual and extraordinary threat with respect to… a national emergency” – to plainly indicate that Congress meant to give the president the authority to enact the sweeping, worldwide tariffs he announced earlier this year. In fact, the IEEPA says nothing about tariffs at all. 

The practical problem for Trump as the case heads to the Supreme Court is that the “major questions” doctrine is a recent favorite of the conservative justices. In 2023, for example, all six of the Court’s conservatives used the very same principle to strike down Biden’s student debt relief program. If Congress meant to empower the president to hand out billions of dollars to borrowers, the Court’s right-leaning justices concluded, it would and could have said so clearly in a law. In the absence of any such explicit authorization, the Court found, Biden’s plan was unconstitutional. 

In fact, the Court’s modern conservatives created the “major questions” doctrine in a 2022 case that struck down clean air regulations issued by the EPA, to the consternation of the three dissenting liberals. Justice Elana Kagan accused the majority of “magically” creating the concept to engineer a preferred policy outcome. 

Against that background, let’s count heads in anticipation of the Supreme Court’s ruling on the tariff case. We can safely predict where Justices Kagan, Sonia Sotomayor, and Ketanji Brown Jackson will wind up: Against Trump. They can get there several ways – the “major questions” doctrine being the most direct route  – and one of the safest bets in the law right now is that the liberals will oppose Trump’s major policy initiatives, one way or another. 

That leaves us with the six conservative justices. If two join the liberals, Trump loses. 

Don’t count on Justices Clarence Thoms and Samuel Alito crossing over. Sure, they loved the “major questions” doctrine when it yielded conservative policy outcomes, but they’ll likely adopt some convoluted explanation why it doesn’t apply now (magically, perhaps, to use Kagan’s characterization). 

But, in my view, at least two (maybe more) of Chief Justice John Roberts and Justices Neil Gorsuch, Brett Kavanaugh, and Amy Coney Barrett are likely to stand on substance and apply the same “major questions” doctrine they have recently created and embraced. It takes too much tap-dancing to get around it in the tariffs case. Nor do I suspect these justices are especially enamored with Trump’s use of an emergency statute in a plainly non-emergent situation, or with his tariff policy writ large.  

Despite the common assertion that the Court’s conservatives predictably do whatever Trump wants, the reality is that Roberts, Barrett, and Kavanaugh have, at times, rejected his positions on key initiatives. In fact, the President reportedly has fumed behind the scenes at his three appointed justices, especially Barrett. And Roberts, as Chief, has made it his mission to avoid politically divisive, six-to-three outcomes in major cases. He has often failed, of course, but he’s plainly aware of the perception issue. 

Even if Trump loses the tariffs case, it’s already clear what he’ll do next. On the legal front, administration officials have vowed that they’ll try again, using a different law to enact the tariffs. Trump’s political opponents may find this approach exasperating, but there’s nothing improper about it. For example, after the Supreme Court struck down Biden’s first attempt to forgive student debt, he tried again under a different law (again, unsuccessfully). Keep in mind that the Supreme Court does not rule on policies: Are tariffs legal? Can the president forgive student loans? Rather, the justices determine whether the use of a particular law to enact a given policy passes constitutional muster. A policy might work under one law but not another. 

And a Trump loss in the Supreme Court might turn out to be a political win. He (and the country) could be spared the potentially calamitous economic effects of the tariffs, about which conservatives and experts alike have warned. And, for the rest of time, whenever any economic indicator blips – a lukewarm jobs report, an infinitesimal inflation bump – Trump will simply blame the justices: If only those activist hacks would’ve let me have my big, beautiful tariffs, everyone would’ve been rich and none of this would’ve happened. 

The Court’s conservatives created the “major questions” doctrine three years ago and have deployed it since then to gut major Democratic presidential initiatives. Now what’s gone around is coming around, and there’s little the Court’s conservative middle can do to dodge it now.