Bruce Bartlett, a conservative political and economic writer, has written an interesting confessional piece, well worth reading in its entirety. It has two main topics: What happens when a proper study of data makes someone change his/her mind, and what happens when that new interpretation of the data conflicts with that person's earlier political and economic beliefs.
Bartlett has come to disagree with certain basic conservative tenets, and in that disagreement has come to find himself shunned by the conservative community that used to be his spiritual home. One long quote suffices for the purposes of this post:
A couple of weeks before the 2004 election, Suskind wrote a long article  for the New York Times Magazine that quoted some of my comments to him that were highly critical of Bush and the drift of Republican policy. The article is best remembered for his quote from an anonymous White House official dismissing critics like me for being “the reality-based community.”
The day after the article appeared, my boss called to chew me out, saying that Karl Rove had called him personally to complain about it. I promised to be more circumspect in the future.
Interestingly, a couple of days after the Suskind article appeared, I happened to be at a reception for some right-wing organization that many of my think tank friends were also attending. I assumed I would get a lot of grief for my comments in the Suskind article and was surprised when there was none at all.
Finally, I started asking people about it. Not one person had read it or cared in the slightest what the New York Times had to say about anything. They all viewed it as having as much credibility as Pravda and a similar political philosophy as well. Some were indignant that I would even suspect them of reading a left-wing rag such as the New York Times.
I was flabbergasted. Until that moment I had not realized how closed the right-wing mind had become. Even assuming that my friends’ view of the Times’ philosophy was correct, which it most certainly was not, why would they not want to know what their enemy was thinking? This was my first exposure to what has been called “epistemic closure”  among conservatives—living in their own bubble where nonsensical ideas circulate with no contradiction.
Something like epistemic closure is happening all over the political marketplaces, not just on the right. But the phenomenon is strongest on the right, the isolation and insulation are the most extensive on the right, and the Fox News provide a news source which doesn't look as filtered as it really is. Thus, we get large groups of individuals conversing mostly with each other, reading only about certain types of news and only with a certain tilt, and the outcome is, as you may have noted, pretty disastrous: People don't only hold different opinions, they assume completely different "facts."
But as we all know, we are entitled to our own opinions but not to our own facts. (You are also entitled to my opinions, heh.)
I've tried to understand the phenomenon of hedgehoggery (my earlier term for "epistemic closure"). I can see the emotional benefits of having the world presented only from the angle the audience already believes to be the correct one. It gives one a warm feeling, righteous anger and a peace of mind. Still, the costs of being misinformed can be enormous, and hedgehoggery all across the net, for instance, means that I frequently get into debates with people who really don't have the correct information. It's not possible to have a debate in less than a lifetime if the basic premises and actual facts are all under debate, too. And that's what I see more and more often. The dangers in all this are that we cease to remember how to talk to people across the political aisles of various types.
How to avoid all this? There are no easy answers. The first step is to be aware of these dangers, the second step to create some neutral places for debate, with extremely good moderation and extremely careful links to sources of information. Is there any incentive to do that, for anyone? I'm not sure.
Now, when I wrote in the title that "Bruce Bartlett saw the light" I didn't necessarily mean that he saw the light because he is now ever-so-slightly closer to my views. I meant that it's like working in a large, darkened room, with just a small bulb burning in the desk lamp, and figuring out the room from that angle. If you then turn on all the lights in the room, you suddenly see bookshelves, spider webs, those shoes you couldn't find yesterday, those unpaid bills and so on. You see more when the lights are on.