Supposing that RFK had lived but gone on to lose the Democratic nomination to Hubert Humphrey in 1968, he would have been a major contender for 1972 provided that Nixon still wins in '68. (Some might argue that if RFK had lived to endorse and possibly campaign for HHH then the Dems would have carried the day in '68, however Kennedy's support for Humphrey would be lukewarm at best and I don't think this would put HHH over the top). Given that George McGovern of all people was able to upset Humphrey in the 1972 primaries, it's not out of the question that had a surviving Kennedy decided to challenge Nixon he would have beaten Humphrey this time around and he'd win the Democratic nomination. What would be the result of a Nixon vs. RFK matchup?