Noam Scheiber dismisses the idea that Hillary Clinton has any kind of advantage with the white working class over Obama in a general election match-up with McCain:
I mention this now because there seems to be some support for it in the latest Washington Post-ABC poll. According to the WaPo write-up, Clinton and Obama do more or less equally well among working-class whites in a matchup with John McCain: “Against Obama, McCain is ahead among whites without college degrees by 52 percent to 40 percent, not that different from McCain’s advantage over Clinton in this new poll.”
If you believe, as the CW has it, that Hillary wins certain working-class whites whom Obama would lose to McCain, then the math says Obama must be winning certain working-class whites that Hillary would lose to McCain.
My guess is that Hillary may or may not help you with the former, but she’d almost certainly hurt you with the latter.