Julian Sanchez defends his thesis:

I’ve written a bit lately about what I see as a systematic trend toward “epistemic closure” in the modern conservative movement. As commenters have been quick to point out, of course, groupthink and confirmation bias are cognitive failings that we’re all susceptible to as human beings, and scarcely the exclusive province of the right ...Yet I can’t pretend that, on net, I really see an equivalence at present: As of 2010, the right really does seem to be substantially further down the rabbit hole.

Yglesias offers an alternative. Noah Millman moderates. I think Millman's emphasis on the South is critical:

Blame the South. The argument, in a nutshell, is that a successful political coalition in America cannot be dominated by the South, as the GOP currently is. The South is a distinct region in America, significantly different in history and political culture from the rest of the country. Moreover, regional identity in the South is manifested substantially in opposition to the rest of the nation. A political movement dominated by the South will necessarily manifest a political culture that is more similar to that of the South than to that of the rest of the nation, and that political movement is also going to absorb this oppositional element of Southern identity, and will necessarily become overly invested in intellectual shibboleths. What looks like epistemic closure is really just identity politics.

Noah's comments on the Iraq war are also trenchant. I think his major omission is the ideological-industrial complex - the FNC/Talk Radio money machine that holds everything else in thrall. And then there's the authoritarian leader worship of the Bush-Cheney war years, when party discipline was all the more vital because the policies themselves were so incoherent and practically disastrous.

I certainly feel, of course, total alienation from people I once saw as fellows in a broad world of ideas. I don't think I'm alone. I just think I'm rare in saying so in public day after day. The perils of blogging, I guess. And I fear the handful of us out there in total dissent - now with extra Frum! - somehow enable the others to stay silent.