A Canadian journalist on the invincible  ignorance of Birthers, 9-11 Truthers and other cultish sorts:

“[W]hen you debate a conspiracy theorist it’s like challenging an NFL football team to a game. Because conspiracy theorists have spent their lives memorizing every single detail necessary to win an argument. Even if you have the facts on your side in an abstract way, you’re not going to win an argument if you have to go look at Google or go to the library to rebut every single point. They have hundreds of little confusing bits of information that they can throw at you. Even if you bat away 99 of them, the 100th, if you don’t repute it immediately, they’ll say, “Ah ha! There’s an anomaly that you can’t explain.” The way they define the terms of the debate is that they just have to get you on one point, and then they have destroyed the validity of the conventional narrative.

“The second thing is, it’s a cult. And you can’t disabuse a cult member of their beliefs, because it’s central to their identity. Hardcore conspiracy theorists are attached to their conspiracy theories with the same force of conviction that religious adherents are attached to their religions. You can’t rationally convince someone not to be a Christian or a Scientologist. That’s their identity, that’s who they are.”