They get bitter, they cling to guns or religion or antipathy to people who aren't like them or anti-immigrant sentiment or anti-trade sentiment as a way to explain their frustrations.
Yeah, that's pretty much Tea Partiers in a nutshell. It covers just about the whole range of faux "issues" they pretend to have something about which to say.
I'm becoming more and more of the mindset that, rather than focusing on how dumb the Tea Party thing is, we ought to try and remember what the root causes are of this populist vomit-rage. In the quote from 2008, Obama was referring to towns in the Midwest suffering from staggering job losses. While cynical GOP strategists, religion, and Beckian journalism have plenty to do with the Tea Party movement, in many ways the root cause is frustration with the lack of economic opportunity. Ironically, one might even argue that the Tea Party phenomenon might never have emerged if more liberal policies had been adopted throughout the country...!
So what does this mean in practice? I'm not sure, but one thing it reminds me of is why it's not okay to let the Red States twist in the wind, hoisted by their own petard. It bothers me when people say things like, "Well, who would want to live in Alabama anyway? Fuck 'em." First of all, children growing up in Alabama don't have a choice. Other people may not have much of a practical choice due to job or family situations, etc. And this is just another reason: When any state neglects the welfare of their citizenry, it breeds the kind of populist outrage that fuels movements like the Tea Party -- and that influences politics on a national level.
If Alabama doesn't take care of their own people, then pissed-off Alabamians are going to march on the capital and demand that New York stop trying to look after their citizens too.