Why The Clintons do well in Appalachia- can it be explained?

Writing at Real Clear Politics, Jay Cost argues we can't really understand what rural white voters all are thinking when they vote because all we have to go on is poll data.

Cost uses Appalachia as his template: "Obama's weakest performances (using a map we can't reproduce here) among whites have been in Appalachia, which is traced in solid black. Oxendine has put counties that Obama won in green, counties that Clinton won in blue. Note the expanse of deep, dark blue that moves from Mississippi to New York. This is where Obama has had his greatest problems. This is why Clinton will not drop out next week, even if she loses Indiana. West Virginia comes the week after, and Kentucky the week after that. She's bound to win both, and candidates do not drop out immediately prior to impending victories."

But the polls don't really explain why this is, Cost says.

"...This is a very unfortunate development," Cost continues. "It is particularly debilitating when it comes to understanding Obama and Appalachian whites. As should be clear from the discussion of "latent racism" and the "Bradley Effect," polls are particularly unhelpful here. Race is a hard topic to explore from thirty thousand feet, which is essentially what the polls do.

"What we need, then, is...an expert who is up-to-date on the latest scholarly research, and who has spent time soaking-and-poking in places like Fayette County to see whether people there are willing to vote for Obama. As far as I know, there is no such expert.

"And so, we have no answers, just questions."

On the other hand, Politico's Ben Smith posted a persuasive explanation March 6: we're talking Scotch-Irish in Appalachia. As Senator James Webb describes them in his book, Born Fighting:

The Scots-Irish (sometimes called the Scotch-Irish) are all around you, even though you probably don’t know it. They are a force that shapes our culture, more in the abstract power of emotion than through the argumentative force of law. In their insistent individualism, they are not likely to put an ethnic label on themselves when they debate societal issues. Some of them don’t even know their ethnic label, and some who do don’t particularly care. They don’t go for group-identity politics any more than they like to join a union. Two hundred years ago the mountains built a fierce and uncomplaining self-reliance into an already hardened people. To them, joining a group and putting themselves at the mercy of someone else’s collective judgment makes as much sense as letting the government take their guns. And nobody is going to get their guns.

They're white, Protestant, blue-collar, small town/rural, disproportionately represented in the military, and prone to cross-index grudges. Pitch your arguments to their genetic sense of grievance, and attribute it to some Other who's not like them, and you'll get their votes every time.