Mark is an American legal scholar specializing in constitutional law, constitutional history, and comparative constitutional theory. He is the William Nelson Cromwell Professor of Law Emeritus at Harvard Law School and previously taught at Georgetown University Law Center. He earned his Bachelor of Arts from Harvard College and both a Master’s degree and Juris Doctor from Yale University, later serving as a judicial law clerk to U.S. Supreme Court Justice Thurgood Marshall. Early in his career, he became heavily identified with the Critical Legal Studies (CLS) movement, examining how political power and ideology shape legal frameworks.
His scholarship is characterized by a skepticism of judicial supremacy, advocating instead for populist constitutionalism and returning constitutional interpretation to the public sphere. He has authored dozens of seminal books, including Taking the Constitution Away from the Courts (1999) and Weak Courts, Strong Rights (2008). His work extensively maps how constitutional design resists or succumbs to democratic crises, a theme central to his recent co-authored volume with Bojan Bugarič, Constitutionalism and Its Discontents (2026). In this book, they argue for a “thin” constitutionalism, urging political mobilization over a reliance on high courts to address the underlying economic and cultural drivers of modern democratic backsliding.