Two words:
cognative dissonance.
I really hate the term "cognative dissonance." Probably in the same way that other people hate a certain favorite of mine ... the word "meme." But in this case, I think it's a good explanation for why the media hates Dean.
First off, though, I don't think that it is necessary to provide much evidence here for the media's loathing of anything and everything Dean. All you really have to know is this: "YEAAAAARGH!"
The problem that the media has with Dean can really be boiled down into this:
The media feels that a Democratic candidate should be a classic elite liberal politician, whether from the North or South, someone like John Kerry. Slick, two-faced, willing to tell a lie, shifting with the wind, selling out to different "special interest groups" as convenience dictates and capable of spending as much of the public's money as possible to do it.
This allows the media to perpetuate its story of crafty, dishonest urban Democrats who have made secret pacts with Blacks and Jews to suck the life blood out of the country. On the other side of this story are the well-meaning, good-hearted small town White Republicans who, despite their good hearts, are naive as hell and incapable of dealing with truly complex issues like civil rights and foreign policy. The sleazy Democrats keep the Republicans out of trouble with their cleverness ... and the Republicans keep the Democrats out of trouble by being morally steadfast.
The media hated Clinton because he was a country kid who did well and went to Washington to make it a better place and defied all of the media's expectations about slimy urban Democrats working corrupt party machines.
The media hates Dean because they are once again presented with a Democrat who defies their expectations. Dean isn't urban, he's not slimy, he's not part of a party machine. He doesn't want to increase spending. He wants to let states control firearms. And he's got a lot of other classic non-liberal positions besides.
Now, the media may have nothing against Dean personally. But, if they are going to following their script, they really don't know what to do about him except for to savage him for what he is and savage him for what he is not. Everything he does causes a problem for them. Just witness how flustered Ms. Sawyer became last night when it became apparent to her that Dean and his wife were regular, normal Americans with a great marriage and family.
John Kerry on the other hand ... He is just the media's ideal for what a Democratic candidate should be. Polished, clever, Kerry has one of the most liberal records in the Senate. If you watch him speak, he dwells mostly on promising interest groups exactly what he will deliver to them and reveals nothing about his own views or his own vision. It could be that he has neither and no other goal than to deliver what his consituencies demand of him, in the interest of the country at large or not.
The media knows exactly how to handle such a candidate. They know how to bio him, describe him, describe his history, set him up, compare him to the Republican and track the election all the way to that November Tuesday. It won't take any work. Liberal Kerry v. Conservative Bush. Simple as that.
To cover Dean, the media must step down its pride a bit, admit that they made initial mistakes in their evaluation of him, struggle to analyze how his policies different from Bush and accept that someone is running for president who has a vision that requires some amount of sacrifice in order for the greater good to grow.
I can't imagine that they would do that.
And so they've fought and will fight Dean every step of the way.