From a friend of mine:

One troubling (for Obama) point about "Joe," is that he represents a much broader definition of "white working class male." Joe seemed to admit to making close to $250K, putting him in a pretty nice income bracket, especially for Ohio. When McCain sarcastically said, "Congratulations, Joe, you're rich," he could have been playing it straight. Of course, reality is much more complicated; Joe now claims to be earning much less. However, by implying that you could make $250K and still be "working class," McCain has embraced a whole group of largely ignored voters: successful whites who don't think of themselves as rich. These are the folks who started out in Brooklyn apartments and now have big houses on Staten Island; they're the ones who rose through the ranks in fields like contracting, sales and, yes, plumbing, and now do very well, but still think of themselves as working class, based on their roots and career paths.

More here.