[273]
Historians have debated the factors that led to Johnson's surprise decision. Shesol says Johnson wanted out of the White House but also wanted vindication; when the indicators turned negative he decided to leave.[274]  Gould says that Johnson had neglected the party, was hurting it by his Vietnam policies and underestimated McCarthy's strength until the last minute, when it was too late for Johnson to recover.[275] Woods says Johnson realized he needed to leave for the nation to heal.[276] Dallek says that Johnson had no further domestic goals, and realized that his personality had eroded his popularity. His health was not good, and he was preoccupied with the Kennedy campaign; his wife was pressing for his retirement and his base of support continued to shrink. Leaving the race would allow him to pose as a peacemaker.[277] Bennett, however, says Johnson "had been forced out of a reelection race in 1968 by outrage over his policy in Southeast Asia".[278]
After Robert Kennedy's assassination, Johnson rallied the party bosses and unions to give Humphrey the nomination at the 1968 Democratic National Convention. 