I really like the point Yglesias is making here. His longer post is interesting in its own right, but I'd boil the main idea down to this reminder:
To liberal white men like myself, McCain, Bush and Palin's "real Americans" business certainly is frustrating. We may even get angry about it. But it's also a laugh line. It's funny that McCain and Palin would try to imply that we're not real Americans and that our votes shouldn't count.
To black people, or to women, or to anybody whose history in this country includes a substantial period when they really weren't considered by law to be real Americans, and their votes really didn't count, well, it just isn't funny at all. In fact, it's irresponsible and disgusting and the GOP should take a lesson from this election and just stop it.
The rest of us, of course, should not hold our breath.