But those tensions flared long before the campus protests erupted with the current Israel-Hamas war. Controversial speakers have been disinvited or “deplatformed” at schools around the country since the late 1990s. There is a long history of suppression that includes such prominent scholars as W.E.B. Du Bois, the Black civil rights activist who was “blackballed” from speaking at some American universities over his Communist views, said Samuel J. Redman, a history professor at the University of Massachusetts Amherst. More recent examples include efforts to block appearances by former secretary of state Henry Kissinger and geophysicist Dorian Abbot at the Massachusetts...