The Democrats would be stupid to nominate Hillary. It makes no sense to select someone with such high negatives. And besides, the only time the Democrats have won is when they put 2 southerners on the ticket.
Hillary, born in Illinois and carpetbagger Senator from New York, doesn’t count as a southerner even if she was the first lady of Arkansas.
My family is almost all Democrat - even they can’t stomach Hillary. I would not be surprised to see the sensible Democrats choose Obama simply because they know they can’t win with Hillary... that, and there is a certain amount of being sick of the Clintons (and the Bushes). Obama has run a smart campaign.
(with the exception of Kennedy in 1960).