Spiro Agnew's downfall had nothing to do with the Watergate scandal.
True, but the overall Watergate atmosphere contributed greatly to Agnew's downfall. Absent Watergate, it's quite likely that the Agnew corruption would have been swept under the rug, and he would have served out his term as VP.
Without the Agnew resignation, Ford would never have been a factor. As Mike said, he had no interest in being president or even vp until it was thrust upon him.
Keep in mind that the 1973-77 period would have been a tough one even without Watergate. The economy was doing poorly, largely because of the residual effects of economic mismanagement by LBJ and Nixon.
Nixon's administration signed a tenuous Vietnam "peace" treaty in early 1973 that withdrew American troops, while leave North Vietnamese occupation troops in place in South Vietnam. Nixon expressed determination to enforce the ceasefire accord, meaning that North Vietnam was not permitted to reinforce or add to those troops (a provision they flagrantly violated), but was stripped of the ability to do so as his power ebbed away due to Watergate. Without Watergate, Nixon probably would have renewed bombing of North Vietnam by early 1974, and the Vietnam controversy would have been prolonged, in any case. As it turns out, Nixon was forced to ignore North Vietnamese violations of the peace treaty, but the situation had not yet reached a crisis point when he left office. He passed the problem on to Ford, who basically had no choice but to abdicate on Nixon's promises to South Vietnamese president Thieu and abandon South Vietnam.
The point of all this is is that Ford's abandonment of the South Vietnamese was a large but unspoken reason why Reagan challenged Ford for the 1976 nomination, and the resultant rightward turn in the Republican party. I think that if Nixon had renewed bombing and prolonged the Vietnam controversy, it would have worked against the Republicans, and made a Democratic victory more likely in 1976, because by then Americans wanted no part of the war, especially after Nixon essentially oversold the 1973 peace treaty as promising the end of the agonizing US involvement there.
So I have to vote "none of the above." Without Watergate, the Democratic candidate would most definitely not have been Carter. Humphrey was out for health reasons. Given the likely political alignment and reaction to what Nixon's second term policies would have been, the Democratic candidate would most likely have been a classic liberal in the Mondale-Humphrey mode. Maybe even someone like Ted Kennedy, though not Ted himself because of his personal baggage, which included Chappaquiddick and his severely alcoholic then-wife.
Poll
