I'm Dahlia Lithwick and this is Amicus, Slate's podcast about the courts and the law and the U.S. Supreme Court.

This past Wednesday, the court heard what might well become one of the signature cases of the 2025 term.

The challenge to Donald J. Trump's so-called Liberation Day tariffs put in place to punish foreign countries running a trade deficit against the U.S.

or against Canada just because, well, Canada.

The consolidated cases learning resources versus Trump and Trump versus VOS selections come to the court as challenges to his very, very broadly stated authority to impose tariffs as he sees fit in order to regulate an economic crisis that he has announced is currently happening.

Trump asserts that he can do this under the International Emergency Economic Powers Act of

1977, AIPA, which permits the president to, quote, regulate transactions involving any property in

which any foreign country or a national thereof has any interest, end quote, this power can only be

exercised to, quote, deal with an unusual and

extraordinary threat. Mark Joseph Stern is here to join me for this interview. Hi, Mark.

Hi, Dahlia. On this week's show, we want to recap the oral arguments with Mark Bush. He's the

Carl F. Landegger Professor of International Business Diplomacy at the Edmund

Day-Walsh School of Foreign Service at Georgetown University. He's an expert on international

trade policy and law, and also signed on to an amicus brief on behalf of trade scholars

explaining the history and context of Aipa. Mark, welcome to the show. Thanks so much for having me.

Great to be here. So it certainly sounded to us like Trump's tariffs were not going to survive

contact with the Supreme Court based on our very unscientific nose counting from oral arguments on Wednesday.

But before we get into that, could we just ask you to

lay out the constitutional and statutory game board here so we understand the pieces we're playing

with? Aipa is, as you heard during the oral arguments, the follow-through to the turmoil that was

created when Nixon began to go off gold.

And a lot of what you heard goes back to what everybody thought was learned from that

...