John Ferejohn is the Samuel Tilden Professor of Law at New York University. His primary areas of scholarly interest are political theory and the study of political institutions and behavior. His current research focuses on Congress, law and legislation, constitutional adjudication in the United States and Europe, separation of powers, political campaigns and elections, and the philosophy of social science. He was formerly a professor of Social Sciences at the California Institute of Technology (1972-1983) and a professor of political science at Stanford University and a Senior Fellow of the Hoover Institution (1983-2009).