Edwards performed best in the rural South, particularly the border states where there aren't as many black voters who would have tended to support Obama. He got a sizable chunk of the Oklahoma primary vote even though he'd been out of the race for a while.
A lot of those voters ultimately supported McCain in the fall and many haven't returned to the Democratic fold since then (certainly not in the mid-term elections, anyway).
Why would these "conservative Democrats" support John Edwards when he was arguably more liberal on economic issues than either Clinton or Obama? Or is this just evidence that they were all a bunch of racists who just wanted to be able to vote for a white guy with a Southern accent?
A lot of white Democrats in the South are poor. That's why Edwards, who ran an economically populist campaign ("two Americas"), did so well with them.
