You may be correct that McCain will win among lower-income voters and Obama among higher-income voters in Vermont, but this would be contrary to all recent experience. See Razib’s post on it, or Andrew Gelman’s, who literally wrote the book on this subject.
Gelman is quite gracious about this, by the way:
P.S. As statisticians we’re taught to rely less on our lived experience and on impressions from a weekend visit to Vermont, and more on random-sample survey data. And that’s what I’m doing here. But I have to admit that in many areas of my professional life (for example, in considering strategies for teaching and for research), I rely pretty much only on my lived experience and on the research equivalents of weekend visits to Vermont. Somehow, for things that affect me directly, statistical principles become less important. So I can see how, for a political journalist such as Nordlinger, it can be difficult to discount one’s personal impressions. Nonetheless, I hope he can do so.