THE DANGERS OF EPISTEMIC CLOSURE…. About a week after the midterm elections, David Frum, a former Bush speechwriter, had a very strong piece, explaining how important it is for his fellow Republicans to learn the appropriate lessons from what had transpired over the last two years. At the top of Frum’s list: recognizing the “danger of closed information systems.”

Too often, Frum said, conservatives “wrap themselves in closed information systems based upon pretend information. In this closed information system, banks can collapse without injuring the rest of the economy, tax cuts always pay for themselves and Congressional earmarks cause the federal budget deficit…. As corporate profits soar, the closed information system insists that the free-enterprise system is under assault. As prices slump, we are warned of imminent hyperinflation. As black Americans are crushed under Depression-level unemployment, the administration’s policies are condemned by some conservatives as an outburst of Kenyan racial revenge against the white overlord.”

For poli-sci-minded news observers, this isn’t new — the problem of “epistemic closure” on the right has been a hallmark of recent years. It’s especially common with Glenn Beck acolytes — Beck, Frum noted, offers “an alternative history of the United States and the world, an alternative system of economics, an alternative reality” — but it’s also come to dominate even mainstream conservative thinking.

Much of the right is convinced of their version of reality, because they only interact with media that reinforces that version, giving them a sort of tunnel vision when it comes to reality. Early last year, Jonathan Chait labeled it the “Conservative Misinformation Feedback Loop.”

Jonathan Bernstein had a terrific item yesterday, noting how epistemic closure affected the right’s response to last week’s shootings in Tucson.

…I think we’ve seen an excellent example of this kind of loop over the last week, leading logically to Sarah Palin’s much-maligned address to the nation in which she placed herself front and center as the chief victim of the Tuscon massacre. The truth is that if all Palin knew of the world was what she read on at least one highly prominent conservative Web site, her reaction, and her outrage, would be perfectly understandable.

Here’s what I looked at: I went through every post at National Review Online’s The Corner blog from the first news of the shootings through this morning. That’s a lot of stuff; numerous bloggers post quite a lot of items there, for those of you not familiar with it (and you should be! Read things from all over the place!).

What did I find? First, I should say, a fair amount of shock, grief for the victims, and celebration of the heroic stories of those who saved lives in Tucson. Two reasonable posts about “tone,” one from Heather Mac Donald and one from Kathryn Jean Lopez and Seth Leibsohn.

But beginning very soon after the shootings, and continuing all week, the major theme has been resistance to what was presented as a systematic effort by liberals and the press to pin the attack on conservatives, and on Sarah Palin in particular. It is not presented as a story about specific politicians or pundits who made poor judgments. Nor is it presented as a reasoned discussion of whether extreme rhetoric can have unintended consequences. No; if you read just The Corner, what you’re left with is the impression that a monolithic, capitalized “Left” has been literally accusing Palin of murder.

Jonathan went through several examples, with National Review writers pushing back against arguments and rhetoric that they perceived to be real and outrageous, but couldn’t actually point to.

The point isn’t that NRO is unique. For that matter, there probably were some on the left making unreasonable arguments, though if they were part of some systemic progressive push, they probably should have been easier to identify.

Rather, the key takeaway here is that the right’s reliance on closed information systems — its epistemic closure — once again fueled a skewed vision of real-world developments. Conservatives watched Fox News; they heard Limbaugh; and they read National Review the editorial page of the Wall Street Journal, and RedState; and they started drawing conclusions. The left was blaming Palin and the right for the tragedy, or so they convinced themselves to believe.

As Jonathan explained, “[A]nyone reading just the Corner, or getting their news from such sources, would wind up with a massively distorted sense of what liberals were saying, and what the press was reporting. The conclusions that they would draw from that version of reality might be internally consistent, but would be radically wrong.”

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.