The U.S. Justice Department's second-in-command, Deputy Attorney General Jeffrey Rosen, will don the customary swallow-tail morning coat Wednesday for his debut argument at the U.S. Supreme Court.

President Donald Trump tapped Rosen, a former Kirkland & Ellis senior partner, to be the department's chief operating officer in February 2019. Rosen will represent the United States as a friend of the court in Lomax v. Ortiz-Marquez, a case in which a Colorado prisoner has asked the justices whether a dismissal without prejudice for failure to state a claim counts as a strike under the Prison Litigation Reform Act.

Rosen will face Goodwin Procter partner Brian Burgess, counsel to Arthur Lomax. The deputy attorney general will share argument time with Colorado Solicitor General Eric Olson, formerly a clerk to the late Justice John Paul Stevens and a partner at Bartlit Beck.

Rosen's high court argument follows a long tradition of attorneys general or their deputies making at least one appearance during their tenures. Rosen's embattled predecessor, Rod Rosenstein, now a King & Spalding partner, went to the lectern for the first time in the case Chavez-Mesa v. United States, a drug sentencing case. He won a 5-3 ruling for the government.

"I had the benefit of having done a lot of appellate arguments in the Fourth Circuit, particularly as U.S. attorney (for Maryland), and a number en banc," Rosenstein said in an interview with The National Law Journal. "Obviously you're in a different league in the Supreme Court, but it's the same dynamic."

The case Rosenstein argued involved a sentencing issue and concepts he said were familiar to him. The only difference, he said, was that the case was "baked." Rosenstein explained: "In almost every case before, I had personally written the brief and handled the litigation in district court. It's different when you parachute into a case. I had to spend a fair amount of time studying this record. Obviously it's important to know the law, but it would be embarrassing if you didn't know a fact from the record."

Rod Rosenstein Rod Rosenstein speaks in October at the 18th Annual Legal Reform Summit. Photo: Diego M. Radzinschi / NLJ

The U.S. solicitor's office did two moot courts with Rosenstein, and they were "superb," he said.

"A number of people asked me if it was stressful arguing before the Supreme Court," Rosenstein said. "There was so much stress from all the other issues we were facing at that time, appearing in the Supreme Court was the least stressful. I found the justices to be very cordial. I had experienced more confrontational judges in the Fourth Circuit."

Carrying a 35-year-old favorite folder, a gift from his father, Rosenstein walked into the Supreme Court wearing a morning coat he borrowed from Deputy Solicitor General Malcolm Stewart. "They have a whole closet full of pants," he added.

In Rosen's case, the government has asserted an interest in litigation involving the Prison Litigation Reform Act, or PLRA. There are more than 175,000 inmates in federal custody, according to the U.S. government.

"The United States has a substantial interest in the resolution of the question presented because it is frequently the defendant in suits that are subject to the PLRA," Noel Francisco, the U.S. solicitor general, told the justices.

Other deputies who took their turn at the lectern included: Larry Thompson, who won a 6-3 decision in United States v. Drayton in 2002, and James Comey, who garnered a unanimous decision in Devenpeck v. Alford in 2004.

Rosen's boss, U.S. Attorney General William Barr, is a veteran with three arguments to his name, but none of them since joining the Trump administration last year. As attorney general in 1992, Barr argued Brecht v. Abrahamson as amicus curiae supporting Abrahamson, who won a 5-4 ruling in 1993. Other attorneys general who have argued include Janet Reno, Michael Mukasey and Richard Thornburgh.

Rosenstein offered his successor a bit of advice: Rely on the career professionals in the solicitor general's office to help prepare and make sure to have tough, hard-hitting moots. "You can afford to mess up in a moot, but you can't afford to mess up in the big show," Rosenstein said.