I'm sure Mondale's campaign said the same; after all, those really bad economic numbers in 1982-83 made it seem like a slam dunk to toss Reagan out.
Going to head to head against Obama, the white guilt vote is split, since the balance between a black man and a white woman is pretty even. The 'Anyone but a Republican' and 'Anyone but a Democrat' votes are pretty evenly split as well.
It'd be pretty easy for a 'she quit before, she'll quit again, don't elect a quitter' campaign to tip the scales.
You’re trying to worry about something that isn’t going to gather even a tiny bit of traction.