After two years as a trial attorney and a Special Assistant United States Attorney with the U.S. Department of Justice, Titus worked as a professor of law from 1964 to 1979 at the state universities of Oklahoma, Colorado and Oregon. He was "active in various left-wing-based political causes" during this period, opposing the Vietnam War and supporting homosexual rights and abortion rights. He also worked with attorneys and clients on a number of constitutional cases in his role as a regional director with the American Civil Liberties Union.