I was going to write a reply to Andrew Gelman's recent criticism of Paul Krugman but since everybody beat me to it, I'll limit myself to this post script
P.P.P.S. Maybe the zillion commenters who disagree with me here have a point! I still find it a bit of a stretch for people to claim that reporters’ personal likes/dislikes would have more of an effect on coverage than reporters’ ideologies and partisanship, but I can see the reasoning, which I think roughly goes like this: journalists are trained to not let their partisanship get in the way of their reporting, but they don’t have that same constraint with respect to personal like/dislike. Thus a liberal Democratic reporter who personally liked Bush and disliked Gore might slant the news toward Bush and even feel good about such a slant in that it represents a bending-over-backwards to not simply follow the partisan cue.There are some potentially interesting side questions here about the cultural differences between the sides of the spectrum ( "I am not a member of an organized political party. I am a Democrat."), but time is limited so I'll jump straight to the Cialdini.
As noted, I remain skeptical of this story—-I’d think that, when it comes to a national election, partisanship would trump personality—-but it is a coherent argument, supported by data. Which satisfies the request, posed at the top of this post: “I’d like to see Paul Krugman’s evidence for this.”
If you'll flip to the liking, reciprocation, consistency, and social proof chapters of Influence, you'll find lots of evidence to support this story, much of it from peer reviewed papers. Here are some of the relevant points.
Many people have noted Bush was capable of considerable charm.
Many influential reporters had a long standing and well documented dislike of Gore.
The Washington press corp is small and cliquish, prone to convergent behavior.
Because of the image of a liberal bias and because the GOP is known for pushing back, there are generally fewer consequences for a story that puts a Democrat in a bad light. Admitting you've backed down tends to cause cognitive dissonance which is resolved by convincing yourself you meant what you wrote.
The written word is particularly noted for affecting attitudes. People who put beliefs in writing are much more likely to embrace those beliefs.
Bush literally wined and dined the press corp. (Google "lobster ravioli" and Bush). This kind of gift is big enough to make an impression but not large enough that the reporters could justify a lapse in ethics (if I give you a million dollars to do something bad, it is easier to justify and creates less dissonance). Once again we get reciprocation, cognitive dissonance, modification of attitude.
Finally, we know that people tend to greatly underestimate how easily they can be influenced by any one of these things, but it's when they start reinforcing each other that you can get people to do truly startling things.
So, we have a scenario right out of a social psych book, fairly well documented examples of biased coverage, and an election so close that a major change in the tone of coverage could very probably have changed the result.
I think this one goes to Krugman.