I've always rued the choice of Thomas Eagleton as a running mate, and it's been said Carter sought the vice presidential nomination in 1972. While he was fairly fresh as a Governor, I think it could've been an interesting ticket.
Butterflying away the 'abortions, amnesty and acid' quip and Eagleton's controversial health history, and adding Carter's Deep South origins and Washington outsider status, how does the ticket do?
I'm not exactly expecting them to win the election, but I imagine the gap would be more than a little different from OTL.
(edit: emphasis!)