Julian Davis Mortenson writes on constitutional and international law. His current book project—The Founders' President (under contract, Harvard University Press)—develops a comprehensive account of presidential power at the American Founding. He is also co-authoring a new constitutional law casebook, scheduled for publication by Foundation Press in 2020.

Professor Mortenson is an award-winning teacher and an active litigator. Representative constitutional matters include his work as lead counsel in a pre-Obergefell suit that required Michigan to recognize the marriages of more than 300 same-sex couples; his representation of discharged military service members challenging the "Don't Ask, Don't Tell" law; and his work as one of the principal drafters of the merits briefs in the landmark case Boumediene v. Bush, which secured the right of Guantanamo detainees to challenge their incarceration. He regularly litigates complex transnational matters in the U.S. courts, and has served as arbitrator, counsel, and expert witness in a wide variety of commercial and investor-state disputes.

Before joining the faculty, Professor Mortenson worked at the law firm WilmerHale, in the President's Office of the International Criminal Tribunal for the former Yugoslavia, and as a law clerk for both Justice David H. Souter and The Hon. J. Harvie Wilkinson III. Prior to law school, he was a management consultant with a client portfolio spanning the finance, manufacturing, oil and gas, and information technology industries. Professor Mortenson was salutatorian of his class at Stanford Law School and received an AB in history, summa cum laude, from Harvard College.