Mark joined the Becket team in 2011 and splits his time as Associate Professor at The Catholic University of America, Columbus School of Law, and as Visiting Professor at Harvard Law School. Mark teaches constitutional law, religious liberty, torts, and evidence. He has been voted Teacher of the Year three years in a row by the Law School’s Student Bar Association.

Mark has broad experience litigating First Amendment religious exercise and free speech cases. He has represented the winning parties in a variety of Supreme Court First Amendment cases including Hobby Lobby, Little Sisters, Wheaton College, and Holt. In January 2014, Mark argued before the Supreme Court in McCullen v. Coakley, a First Amendment challenge to a Massachusetts speech restriction outside of abortion clinics. The Justices ruled in favor of his clients 9-0. Mark also led a successful eight-year litigation battle against Governor Blagojevich’s effort to force religious pharmacists to distribute the morning-after and week-after pills.

Mark’s academic writing focuses on the First and Fourteenth Amendments, and has appeared in a variety of prestigious journals, including the Harvard Law Review.

Mark is a widely sought after speaker on constitutional issues, particularly concerning abortion and the First Amendment. Professor Rienzi has been invited to discuss these issues at Harvard Law School, Columbia University Law School, Georgetown University Law Center, Boston College Law School, Notre Dame Law School, the National Press Club, and the Capitol. He has been quoted on constitutional law issues on NPR, in the Washington Times, The New York Daily News, and the Chicago Sun-Times. Mark has also been featured on the Kelly File, Fox News Sunday, Your World with Neil Cavuto, Geraldo at Large, CNN Tonight, CNN Live, Andrea Mitchell Reports, and Wall Street Journal Live.

Prior to joining Becket, Mark served as counsel for the litigation department and the intellectual property litigation practice group of WilmerHale LLP. His practice focused on complex civil and appellate litigation with a particular emphasis on intellectual property and First Amendment issues. Prior to joining WilmerHale, he served as law clerk to the Hon. Stephen F. Williams, senior circuit judge for the U.S. Court of Appeals for the D.C. Circuit. Prior to that, Mark was an editor of the Harvard Law Review, and earned his J.D. from Harvard Law School and B.A. from Princeton University, both with honors.