Sign up for the Slatest to get the most insightful analysis, criticism, and advice out there, delivered to your inbox daily.

President Donald Trump’s “Day of Liberation” tariff announcement and the subsequent catastrophic effect on global economies raised a lot of questions about how math works. But under it all, there lurks a legal question: Are these tariffs even legal? On this week’s episode of Amicus, Dahlia Lithwick and Mark Joseph Stern discussed both the legal justification for the sweeping actions and the first legal challenge against them, filed by a historically pro-Trump group. An excerpt of their conversation, below, has been edited and condensed for clarity.

Dahlia Lithwick: Can you start with what should be the simple part? What is the legal basis for the Trump administration’s claim that these tariffs are within his authority? 

Mark Joseph Stern: There is a federal statute, the Trade Act, that gives the president sweeping discretion to impose tariffs, but Trump has not invoked it for this round of tariffs—probably because it still has some limitations and procedural requirements that could take a little while to comply with. So, instead, Trump has tried to find a shortcut by invoking the International Emergency Economic Powers Act. This is a very broad law that allows the president to declare an emergency “to deal with any unusual and extraordinary threat, which has its source in whole or substantial part outside the United States,” though it doesn’t define those terms. It says that once a declaration of emergency is in place, the president may regulate “any property in which any foreign country or any national thereof has or has had any interest.”

A word that does not appear in the statute is tariffs. This is not a tariff statute. This is a broad and vague national-emergency law that the president is attempting to rewrite into a blank check that allows him to slap massive tariffs on nations across the globe with no legal process, no clear authority from Congress, and no procedure that would allow the countries facing tariffs to get free of them.

And that is the language from which Trump derives this sweeping authority to do something that should be done by Congress, which is: impose massive tariffs that translate into a huge tax hike on all American consumers?

You said that this authority “should” belong to Congress, but to be clear, it does belong to Congress: In the Constitution, it is expressly assigned to Congress, not the president. And, again, Congress has enacted a law delegating the tariff power to the president—but Trump hasn’t invoked it here! Instead, he has invoked this emergency law. And what is the emergency? For some countries, he has specific gripes; he says, for instance, that there are illegal shipments of opioids from China that he can somehow solve by imposing these tariffs. But his overarching complaint, as our friend Ian Millhiser points out at Vox, is “the domestic economic policies of key trading partners and structural imbalances in the global trading system.” Ask yourself whether that is the kind of urgent, pressing national emergency that Congress was contemplating when it enacted this law.

Let’s talk through the lawsuit that was filed almost immediately by the New Civil Liberties Alliance arguing that these tariffs are illegal. The NCLA is a conservative entity that has been allied with the Trump administration and was very recently toasting DOGE, MAGA, and all the right’s big wins. The NCLA argued one of the cases that took down Chevron, and it previously hired Jeffrey Bossert Clark, one of the legal organizers of Trump’s efforts to overturn the 2020 election. This is not a politically expedient suit for these guys, right? 

It is very surprising to see the NCLA be the first out of the gate. They are closely aligned with the Trump administration; their main goal is the demolition of the administrative state. Yet they have filed this lawsuit invoking the major-questions doctrine to argue that the imposition of these tariffs is the kind of question of “vast economic or political significance” that, according to the Supreme Court, Congress must expressly authorize by statute.

I think that is a plausible argument. But I’ll note that so far in the life of the major-questions doctrine, SCOTUS has only ever invoked it against Joe Biden. The court used it to strike down Biden’s Clean Power Plan, which would have restricted carbon emissions at coal-fired power plants, and notoriously invoked it to strike down Biden’s student-loan-relief plan. I think that’s notable because the loan-relief plan was also enacted under an emergency law, the HEROES Act, which was passed after 9/11 and gave the executive branch broad discretion to forgive student loans when there is a national emergency. The administration said: “COVID is a national emergency! We need to forgive these loans!” The Supreme Court swatted it down and said that that wasn’t the kind of relief Congress was thinking of.

Ben Mathis-Lilley Read More

In some ways, then, this case is a big test for the major-questions doctrine. Is it something conservative justices whip out when they want to assert a free-floating veto over policies of Democratic administrations they don’t like? Or can this be a legitimate, neutral principle of the law that can be wielded against Republican administrations too?

I think we need to end on a legal-realism note here: In the end, does it even matter if SCOTUS invokes the major-questions doctrine? Is the court really in a position to stop what already looks as if it is going to be a massive, debilitating global recession? 

I do want to reflect on how depressing it is that we are hoping, for the sake of the global economy and people’s livelihoods, that the Supreme Court invokes an utterly made-up doctrine with no basis in law or the Constitution to save this country from the president it elected. If the court does this, is that really a win for the law? I certainly don’t want to lend the major-questions doctrine any more legitimacy than it already has.

This Content is Available for Slate Plus members only A Funny Thing About Attention that Elon Musk Failed to Consider Congress Is Starting to Think It Could Do Something About Trump After All Think You’re Smarter Than a Slate Staff Writer? Find Out With This Week’s News Quiz. This Content is Available for Slate Plus members only I Almost Joined Big Law. I Always Knew What It Would Do When Trump Came Calling.

But beyond that, the federal judiciary is a reactive institution—it reacts to decisions made by the other branches. It reacts to big, fat mistakes made by the American people. Trump ran on tariffs. It is not a surprise he’s doing this. He promised that he would restore the tariffs of the 1890s. That is what he is attempting to do. We are all going to have to pay the price for the choice that the American people made in November. So even if the Supreme Court intervenes, it probably won’t be for weeks, months, maybe even a year from now, at which point Trump’s tariffs could have sent us tumbling into a global recession. Even then, a good decision is not guaranteed. And, as we’ve discussed here, it’s unclear what a “good” decision even looks like for the law.

I think there is some utility in saying that all roads lead back to the Supreme Court decisions that put us where we are today—the presidential-immunity ruling and other terrible cases going back at least to Citizens United. The court is very much the author of an awful lot of the misery we now find ourselves in, and there is clarity in remembering that.

Get the best of news and politics Sign up for Slate’s evening newsletter.