As it happens, I know a bunch of rural white Pennsylvania Republican voters -- pretty much my whole family. And while they're usually reluctant to talk politics with their crazy pinko son/nephew/grandson, I can say that the cultural distraction thesis doesn't really match their outlook. While they're hardly progressives on cultural issues, they're clearly not the anxious culture warriors portrayed by the cultural distraction argument.
Obama's version of the distraction argument (unlike Bill Clinton's 1992 version that many of Obama's defenders have been gleefully pointing to) adds an important element that can take us beyond the standard cultural distraction argument. Obama said that rural whites are "bitter" because the government never seems to be able to help them. By Obama's reasoning, they weren't pulled to cultural issues by devious GOP rhetoric, they were pushed by the failures of both Republican and Democratic regimes to deliver on their promises.
Where I go beyond Obama is to say that once bitterness at governmental failure is on the table, we don't need to invoke guns and religion to explain why those voters are not so keen on the Democratic party. If you're bitter that government has failed, then you're going to be attracted to the party whose message is "government doesn't work, so we want to shrink it -- get it out of your pocketbook and your life. The only legitimate way to get ahead is old-fashioned hard work."
The cultural distraction argument is undoubtedly true for some people. But it's unfortunately tempting to overgeneralize it. It exploits a lot of Democratic weaknesses -- e.g. the desire to see the GOP as evil geniuses, and the feeling that the party is entitled to the votes of certain demographics (see also the cases of Ralph Nader and black people). But I think that for a lot of people, the small-government frame comes first. Indeed, commitment to conservative cultural positions may quite well follow from bitterness-driven commitment to conservative economic positions. If you see the real solution to the country's problems as lying in traditional virtues of personal responsibility, then you'll frame cultural policies differently. Bans on abortion and gay sex, for example, will come across not as government intrusion into people's personal lives that's inconsistent with the small-government mantra. They will come across instead as the government upholding the traditional personal-responsibility ethic (and its associated lifestyle) against irresponsible hedonism.
I think Obama recognizes that if the anti-government sentiment is often primary, rather than cultural conservatism, that gives him a good opening. He's already demonstrated an ability to inspire people to feel like they can have real hope for what a politician may accomplish. He seems more likely than anyone who sought the nomination this cycle to break through that bitterness. The downside is that he may thereby set himself up for a crushing loss in 2012 if he can't deliver (and I doubt he can).