By way of Brad DeLong, I came across this post by Adam Samwick that expresses puzzlement over why Republican healthcare obstructionism hasn't hurt Republicans (or so it would seem; italics mine):
You don't succeed as a political party by denying other political parties the opportunity to craft policy that serves their constituents. You succeed as a political party when you craft policy that serves your constituents.
Actually, for the Palinist Right, which has taken over the Republican Party, that's not true at all. For the Palinists, politics is never about policy, but a politics of exclusivist tribal identity:
Her policy ignorance isn't a bug, it's a feature. Palin is conceptually and intellectually poor because her politics are not about policies, but a romantic restoration of the 'real' America to its rightful place. The primary purpose of politics is not to govern, not to provide services, and not to solve mundane, although often important, problems. For the Palinist, politics first and foremost exists to enable the social restoration of 'real' Americans (think about the phrase "red blooded American") and the emotional and social advantages that restoration would provide to its followers (obviously, if you're not a 'real' American, you might view this as a bad thing...). Practicalities of governance, such as compromise and worrying about reality-based outcomes, actually get in the way. Why risk having your fantasy muddied by reality?
Put another way, obstructionism is exactly what the Palinists want, even if it's not good policy. That's just not a concern of theirs.
In an off-year election, there's no reason to think that the Republican strategy of mobilizing the Palinists won't work. Yes, with high turnout, it would be a poor strategy, as 2008 showed. But with economic discontent, and a demobilized Democratic rank-and-file, the political calculus is clear, if cynical.