For appellate adversaries of Sidley Austin partner Carter Phillips, the announcement on April 29 that he would chair the firm’s executive committee starting next year may have been cause for celebration. With a promotion like that, they might have figured that Phillips would be too busy to keep arguing, and winning, against them.

No such luck. Even though he’ll be running a firm with more than 1,500 lawyers worldwide, Phillips plans to continue arguing before the U.S. Supreme Court at roughly his current pace, averaging four or five turns at the lectern every term. He has argued 76 cases before the Supreme Court — more than any other person now in private practice.

“I am excited and honored to be selected to serve as the co-chairman and soon to be the chair of the firm’s executive committee, but I do not expect that to affect my appearances before the Supreme Court,” Phillips said recently. He may curtail his work in other appellate courts — although even there, he said, he’ll still represent “the firm’s best clients for their most important cases.”

Phillips said that his plan to continue his appellate advocacy can be seen as a tribute to the “deep bench” of Sidley’s 75-plus-lawyer appellate practice: “They make my job much easier.” And that depth does not start and end at the nation’s highest court, Phillips said. “What has become clear over the past several years and particularly this year is that more and more clients accept the idea that specialized appellate expertise extends beyond the Supreme Court.”

Partner Joseph Guerra, a global coordinator of Sidley’s appellate practice, agreed. An example, Guerra said, was the firm’s work with utility companies that were hit with suits over greenhouse gas emissions. “We were involved from the beginning motions to dismiss,” he said. At the Supreme Court, partner Peter Keisler secured a landmark 8-0 ruling last June finding that the suits were pre-empted by federal law.

This term, Sidley has already won significant cases before the high court. In Florence v. Board of Chosen Freeholders, Phillips prevailed, 5-4, with a decision upholding strip searches for incoming jail inmates.

But his best-known case is still pending: FCC v. Fox, in which Phillips represented television networks challenging federal restrictions on broadcast indecency. Phillips is expecting multiple opinions from a Court divided over how to approach the First Amendment issue. “How the votes will shake out on these alternatives is the $64,000 question,” he said. — Tony Mauro