In the last page of the article Perlstein raises another point, which I find fascinating. Loud public affirmation of things that people at some level know are not true serves as a group bonding thing. Here he is on the Romney campaign:
Lying is an initiation into the elite. In this respect, as in so many others, it’s like multilayer marketing: the ones at the top reap the reward... Sneering at, or ignoring, your earnest high-minded mandarin gatekeepers—“we’re not going to let our campaign be dictated by fact-checkers,” as one Romney aide put it—is another part of closing the deal. For years now, the story in the mainstream political press has been Romney’s difficulty in convincing conservatives, finally, that he is truly one of them. His lying—so dismaying to the opinion-makers at the New York Times—is how he has pulled it off once and for all.Knowing deep inside that something isn't true makes it bizarrely more emotionally compelling to a certain kind of person. Orwell wrote quite a bit about this. For example I think those people who make a big fuss saying 'Obama is a Muslim' don't really believe it. And in a funny way the fact that they know it isn't true makes it more exciting to say it, and hang out with other people who say it. Or you know 'Homosexuals are going to inject our children with AIDS' or whatever bullshit. It excites them in an unhealthy way I think, because they know it isn't true, but they can all get together and say it to each other.
If I try to put it in a nice way, some people are strongly attuned to group cohesion and group membership - which is a natural human thing - and affirming an untruth in solidity with others emphasises the strength of their social ties. Just like for a different kind of person affirming 'the truth' against social unpopularity is quite thrilling in a different way.