Joseph Massad started raising eyebrows on the Columbia campus around 2002. That spring, students circulated a petition calling for the political scientist’s dismissal; one, writing in The Columbia Daily Spectator, cited a lecture from Massad’s elective, “Palestinian and Israeli Politics and Society,” as evidence of a growing climate of anti-Semitism, likening the talk to a swastika tagged on the wall of a campus bathroom. At a pro-Palestine rally that April,...