During this period, Marius also became an outspoken critic of the Vietnam War and an early organizer of protests against the conflict, as well as against the Ku Klux Klan. Most notably, shortly after the Kent State shootings he co-organized a protest at a 1970 Billy Graham evangelistic crusade rally in the university's football stadium at which President Richard Nixon was an announced, invited guest. Although Marius' plan was for the 1,000 or so anti-war protesters to hold a "silent" protest amid the 70,000 pro-Graham spectators in the stadium, the protest turned unruly.