Following the Tet Offensive, the struggle to define the war intensified. The most widespread antiwar activity during 1968 was mobilizing behind the presidential campaigns of Eugene McCarthy and Robert Kennedy. Peace forces coalesced at the beginning of 1968 for what many perceived as a quixotic effort to replace a president who had promised peace with one who would actually secure peace. Lyndon Johnson’s withdrawal from the race in late March inspired a realistic potential for an antiwar Democratic Party nominee. Kennedy’s death in early June ended that hope, however, and strained the collaboration between movement insiders and outsiders. Street demonstrations and growing dissent within the military worked in conjunction with persistent critics within the federal government. Liberal emphasis on electoral campaigns reduced their impact in the national coalition. Leftists, radicals, and the counterculture played a greater role in the spring National Mobilization, the nationwide student strikes, and the August confrontation in Chicago. The government used the courts to deter ongoing draft resistance but without noticeable effect.