Another historical "What If?" topic: Hubert Humphrey defeats Nixon in 1968.

I think you can say that public opinion had turned against the war, as it was being then waged. But remember, Nixon’s election campaign theme was “peace with honor,” which of course implied an end to the war. His policy of Vietnamization – build up the South Vietnamese while gradually withdrawing US troops – gave the public the hope of an end to the war without a precipitous US pull out.