Fearing they would split the anti-Vietnam war vote, Kennedy tried to persuade candidate Eugene McCarthy to drop out of the race. President Johnson eked out a narrow victory over McCarthy in the New Hampshire primary.
Johnson's weak showing led to his surprise announcement later that month not to seek re-election, leaving the race wide open. His VP Huber H Humphrey threw his hat in the ring as well.
Barely two months later, Robert Kennedy would himself be dead, succumbing to three shots from a .22 after winning the California primary.