I might depend on which working class "Democrats" turn out. I think it is all very fluid. Both candidates are pretty well liked in general, which also makes things fluid.
If it were just "the working class," I'd agree. But whenever you add "Democrats" to a phrase, you have trouble finding a group that's going to even come close to voting McCain.
It's the swing baby. There are not going to be any seminal cohort moves in this election I don't think, although I still hope my little demographic cohort (and yours it appears) does move substantially in critical precincts not in my state.