Peter Keisler. Photo by Diego M. Radzinschi/ALM

The four lawyers set to argue Thursday in the blockbuster AT&T antitrust case in Washington bring decades of appellate experience and long ties to some of the country's biggest law firms.

The U.S. Court of Appeals for the D.C. Circuit will hear the U.S. Justice Department's appeal for at least one hour, and the court has picked its ceremonial courtroom—featuring marble statues of historical and Biblical figures—as the venue. The room will hold hundreds of expected observers. Get in line early.

“Only individuals who actually plan to attend the argument will be allowed to line up inside the courthouse for the arguments. 'Line standers' are not permitted. No one will be allowed to hold spaces for other individuals,” the D.C. Circuit said in an advisory this week.

The six-week AT&T trial in front of U.S. District Judge Richard Leon generated thousands of transcript pages—and a 172-page opinion in June. Leon, employing his characteristic penchant for exclamation points, resoundingly rejected the government's claim that AT&T's merger with Time Warner would harm consumers.

Here's a snapshot of the four lawyers who will make their arguments Thursday in front of D.C. Circuit judges Judith Rogers, Robert Wilkins and David Sentelle. AT&T's lawyer will get 30 minutes, which will be shared with an amicus party. The government was allotted 20 minutes. Another friend-of-the-court, supporting neither side, was granted 10 minutes.

➤➤ Arguing for AT&T: Peter Keisler. The Sidley Austin appellate veteran, who served as acting attorney general under the George W. Bush administration, has long stood as a go-to lawyer for companies challenging government actions on appeal. Co-leader of the firm's Supreme Court practice, Keisler was a regular presence in court during AT&T's antitrust trial and will be a familiar face before the D.C. Circuit on Thursday. He argued against the Federal Communications Commission's net neutrality rules and the Obama administration's decision to prevent the construction of the Keystone XL pipeline. Bush picked Keisler for a D.C. Circuit seat, but the nomination was scuttled by a Senate filibuster.

“The Department of Justice's suit to block the transaction was the United States' first litigated challenge to a vertical merger in four decades,” AT&T's lawyers wrote in their brief. Other Sidley Austin lawyers working with Keisler on the appeal include Joseph Guerra; co-leader of the firm's Supreme Court team; Jonathan Nuechterlein and C. Frederick Beckner III, co-leaders of the firm's communications regulatory practice; Richard Klinger; and Kathleen Mueller. AT&T also retained O'Melveny & Myers. O'Melveny partner Daniel Petrocelli in Los Angeles was lead trial counsel for AT&T. Read the AT&T D.C. Circuit brief here.

➤➤ For the Justice Department: Michael Murray. Murray, a top lawyer in the front office of the Antitrust Division—now led by Makan Delrahim—made his D.C. Circuit argument debut in September, defending the IRS against a suit seeking President Trump's tax records. The AT&T argument will be his third in the D.C. Circuit. Murray, who oversees the appellate team in the antitrust division, has argued in five appeals courts overall. He joined the antitrust division just a few months ago from the office of Deputy Attorney General Rod Rosenstein, where he had been serving as counsel and associate deputy attorney general. Murray joined the Justice Department last year from Jones Day, where he was an associate. “Mike has significant appellate experience, including as a law clerk for Justice Anthony Kennedy,” Delrahim said in remarks last month.

Murray wasn't on the opening brief the Justice Department filed in the D.C. Circuit in August. The brief was signed by Mary Helen Wimberly, a former Hogan Lovells appellate lawyer who joined the Justice Department last year. “The outcome of this appeal will shape the future of the media and telecommunications industries for years to come by setting the standard for determining whether industry participants will be permitted to merge into vertically integrated firms that control valuable programming content as well as the means of distributing that content to consumers,” Justice Department lawyers wrote. Read the brief.

Mayer Brown's Andrew Pincus, speaking at the 18th Annual Legal Reform Summit, held at the U.S. Chamber of Commerce in Washington, on Wednesday. Photo: Diego M. Radzinschi/ ALM.

➤➤ Arguing for 37 economists and former government officials: Andrew Pincus. The Mayer Brown appellate partner knows his way around the D.C. Circuit and U.S.Supreme Court. A former assistant solicitor general and Commerce Department general counsel, Pincus counts the U.S. Chamber of Commerce among his clients and has also represented AT&T. Pincus argued in 2010 for the company in AT&T Mobility v. Concepcion, where the Supreme Court bolstered the power of arbitration agreements. He was among the highest-profile opponents of the Consumer Financial Protection Bureau's effort to prevent banks from using arbitration clauses to block consumer class actions.

Pincus was on the brief with Mayer Brown partners Michael Kimberly and Mark Ryan, who leads the firm's antitrust and competition group. “The district court correctly applied economic analysis to assess the effect of this vertical merger on consumers. It found no credible evidence of an anticompetitive effect. At the same time, the district court did find credible evidence that the merger would produce efficiencies,” the Mayer Brown lawyers wrote in their brief, supporting AT&T. Read the amicus brief here.

➤➤ Arguing for 27 antitrust scholars: Eric Citron. The Goldstein & Russell partner, allotted 10 minutes of argument time, represents professors from law and business schools across the country, including New York University School of Law; Stanford Law School; and Harvard Law School. The brief was filed in support of neither side. “We believe that the district court made significant errors of economics, law, and logic in applying the government's theory of competitive harm to the evidence presented at trial, and that neither these errors nor certain extreme positions advocated by the defendants below should be enshrined into law,” Citron wrote.

Citron is a former clerk to justices Sandra Day O'Connor and Elena Kagan. He formerly was a senior associate at Wilmer Cutler Pickering Hale and Dorr, and he served as counsel to the assistant attorney general in charge of the Justice Department's Antitrust Division. Citron is involved in several pending cases in the D.C. Circuit where he is representing a party against the Federal Energy Regulatory Commission. Read his D.C. Circuit AT&T amicus brief here.

Read more:

AT&T Judge Richard Leon Wasn't Mocking Trump! Exclamation Points Are His Mark!

Justice Dept. Lawyer Faces Wrath of Judge Who's Still Weighing CVS-Aetna Deal

Sidley Austin's Keisler Takes on More Formal Role for AT&T in Antitrust Battle

AT&T Case 'Will Shape the Future,' DOJ Tells DC Circuit in Opening Brief

Read the Decision: Judge OKs AT&T-Time Warner's $85B Merger