Our litigator of the week is Neal Katyal of Milbank, who represented a group of small U.S. businesses that challenged President Donald Trump’s sweeping, signature wave of tariffs at the U.S Supreme Court. Last week, in a 6-3 decision, the court held that the obscure law cited to justify the tariffs—the International Emergency Economic Powers Act of 1977—didn’t grant the president the authority to implement them during peacetime. In the majority opinion, Chief Justice John Roberts wrote the president’s reading of IEEPA would grant him the independent power to impose tariffs on imports “from any country, of any product, at any rate, for any amount of time.” “It would replace the longstanding executive legislative collaboration over trade policy with unchecked Presidential policy making,” Roberts wrote. “Congress seldom effects such sea changes through ‘vague language.'” Lit Daily: Who were your clients and how would you characterize what was at stake here? Neal Katyal: The rule of law and constitutional government was at stake. The Supreme Court has rarely, if ever, struck down a president’s signature policy over the 200-plus years of the republic, but it did here, because it recognized what a ruling the other way would have meant. Our clients were five small businesses. Early on, I was approached to lead tariff litigation on behalf of one of the nation’s largest companies, but they ultimately got cold feet, as did every other major company and trade association. It took the guts of these small businesses to bring the case.

How did this matter come to you and the firm? The Liberty Justice Center, a brilliant group of advocates in Chicago, filed the case on behalf of the small businesses. They argued the case in the trial court and won. At that point, Liberty Justice Center asked my team at Milbank and another law firm, Wilson Sonsini, to join for the Court of Appeals and beyond.

Who was on your team and how did you divide the work? I am blessed with the best team in the business, hands down. My partner Colleen Roh Sinzdak was my right hand on everything; she is the most brilliant legal strategist I know. Her last SCOTUS argument was in the Nvidia case, where she beat me 9-0. As a result, I hired her out of the Solicitor General’s Office to join me at Milbank. Watch out for her, one day she will be an excellent U.S. Solicitor General. Our Milbank associates (Samantha Ilagan, Jessica Huang and Chase Hanson) and our researchers (Kami Arabian and Holland Bald) all played key roles. The Liberty Justice Center was amazing, especially Sara Albrecht, Jeff Schwab and Reilly Stephens. Sara doesn’t have a law degree but knows more law than most lawyers I’ve met.

As always for me, the moot court process was the lynchpin of my preparation. All of them mooted me, along with dozens of others. In total, I did 12 moots.

Give me the brief lay of the land on these challenges to the International Emergency Economic Powers Act reasoning for these tariffs. What was your route, in particular, to the Supreme Court here? It is the exact same structure as my first Supreme Court argument, which was about the Guantanamo military tribunals. There I basically said, “Look, I don’t know if we need military tribunals or not, but the one thing I’m sure of is that the president can’t do it with the stroke of his pen. Congress must authorize it.” Same argument here: “I don’t know if tariffs are a good or bad idea, but the one thing I’m sure of is that a president can’t do it on his own.” It was critically important to me that we litigate the case not about any one president, but about the presidency in general. I’ve taught separation of powers 20 times, written extensively about it and felt like my entire career had been preparing me for this moment.

You split argument time with Oregon Solicitor General Benjamin Gutman. What was your working relationship with the state parties and their counsel like? Incredible, Ben is a brilliant and talented advocate and a wonderful person. I was so impressed with how calm he was; I mean, it was my 54th argument and I felt the pressure. I would do a case with him anytime. I was also very impressed with the State AG offices who worked with Ben. They were chock-full of great insights.

In a case that is as high profile as this one—one where the argument is likely to be consumed by an audience larger than the typical pool of court watchers—do you change how you prepare in any way? As an advocate, does that extra attention affect you at all? It very much does. I have been lucky to have argued some very big cases, starting with my first (Gitmo), or the Voting Rights Act, or the Muslim ban, or Moore v Harper. But in this one, we were asking the court to do something it had never done before. I felt the gravity. I felt the eyes of history. You know every word you say is going to be parsed and analyzed and criticized. Most of all, I felt the deep obligation to be pinpoint-accurate to the court, even though there are all sorts of constituencies pushing me to say one thing or another.

This argument was different than any other because of a campaign to try and replace me with another advocate that unfolded in the two weeks before the argument. Those behind it were not very subtle, and their actions disrespected the court and all involved. They also botched many facts as part of their campaign. Despite that added layer, my clients resolutely stood by me at every turn, which I am so grateful for. But I felt even more pressure to deliver and vindicate their faith in me.

I was very fortunate to have met someone the month before the argument: a brilliant sports performance coach named Ben Crowe. He coaches Agassi and people like that. He made the good point that what I was about to do was similar to his clients—and we then started working together. He was mind-blowingly helpful. I gave the best oral argument I ever could, and Ben helped bring that out in me. It was also tremendously meaningful that my clients had so much faith in me—I felt their support at every turn.

There was an interesting moment in the oral argument where Justice Alito teased you, asking if you ever thought that your legacy as a constitutional advocate would be as “the man who revived the nondelegation argument.” There are clearly advantages to being among the advocates who regularly appear before the court, but are there any drawbacks to being something of a known entity among the justices? There are advantages and disadvantages. Because they know you so well, they can come after you better, as Justice Alito effectively did here. I have spent the last five years consciously studying how to turn that familiarity into a benefit. In particular, I have been taking improv comedy classes. You might ask, what in the world does improv have to do with Supreme Court argumentation? My answer: everything. Improv at its best is not about being funny–it is about truly listening to someone and understanding them, and only after listening can you say something. Also, when you say something, it is a “yes, and”—it builds on what they said, even if it’s hostile. You can see it in the answer I gave there, and in so many other answers. I would get a super-hard question, and I would begin with “thank you,” and I really meant it. Because in the end, Supreme Court litigation is truly a privilege–the chance to hear what a justice thinks and then the chance to try to change their mind. Wow. I’m grateful for that every single day.

What sticks out to you from the majority opinion by Chief Justice Roberts and the various concurrences? I was struck by two things. One, how the Chief Justice mirrored his boss, Chief Justice Rehnquist. His opinion is short, direct, to the point–I wish I could write like that. Second, Justice Gorsuch’s opinion, which is one for the ages.

You wrote in the Washington Post this week: “The government cannot tell courts that refunds are simple and inevitable when seeking relief—and then imply they are complex and distant when the time comes to pay.” You also wrote that you were launching a “task force” of trade law experts and litigators to get those refunds. What can you tell us about that nascent effort? The government in our case already said they would pay the refunds and interest, so I don’t think they can turn around now and claim something else. The courts relied on those submissions to keep the tariff collections going after we won the case in the trial court and Court of Appeals. So yes, we will fight tooth and nail to make sure refunds come back.

What about the new round of tariffs issued under Section 122? I take it that your position is that if the president wants sweeping tariffs, he needs to go to Congress for them. Should we expect another round of lawsuits challenging these tariffs? Yes, once again, the Trump administration already conceded this. They told the Supreme Court and Federal Circuit in our case that Section 122 is unavailable. So, lawsuits will be filed. As I told the Supreme Court, if the president is so convinced tariffs are necessary, he has an easy path: Go ask Congress to authorize them.

What will you remember most about this matter? The teamwork between every member of my group and the Liberty Justice Center was like a beautiful antique watch. So many different moves, each done with synchronicity and respect for the strengths of everyone. It was the privilege of a lifetime.