In a Texas Monthly interview, former White House adviser Dan Bartlett admits that Washington reporters are generally driven by professional incentives, not ideology:

TM: Do you think the press corps is responsible for putting that word out—that the president was lying [about weapons of mass destruction in Iraq]?

BARTLETT: I don’t think they’re purposely doing it. Look, I get asked the question all the time: How do you deal with them when they’re all liberal? I’ve found that most of them are not ideologically driven. Do I think that a lot of them don’t agree with the president? No doubt about it. But impact, above all else, is what matters. All they’re worried about is, can I have the front-page byline? Can I lead the evening newscast? And unfortunately, that requires them to not do in-depth studies about President Bush’s health care plan or No Child Left Behind. It’s who’s up, who’s down: Cheney hates Condi, Condi hates Cheney.

Unfortunately, those incentives are all wrong, as Bartlett correctly points out.