Robb would only have a chance in '88, but he'd probably lose to Bush. Bumpers would butterfly Clinton, since Clinton says in his memoirs he'd have supported Bumpers had he run at any time. I think all these people are too conservative for the Dems, since only 1988 is the last gasp of New Deal/Progressive ideological dominance in the Democratic Party before being replaced by the DLC. They've only had 2 Southern nominees since WWII- LBJ and Clinton. That hadn't been overcome by '88, though by then it was an ideological stigma rather than cultural bias.