Jonah Goldberg comments on media bias, and does a mini-review of Eric Alterman's book in the process, in this WSJ piece. He suggests that part of Alterman's perspective problem is that he's so far to the left that even the liberal media isn't liberal enough to suit him:
(Alterman) simply dismisses the proven fact that the vast majority of journalists admit they are liberal. When nine out of 10 reporters state in a survey that they voted for Bill Clinton, Mr. Alterman counters that Mr. Clinton wasn't very liberal, and that if he had run for president in, say, Belgium or Germany he'd be considered conservative. That's a debatable point, but it doesn't change the fact that in America the press corps clusters almost entirely at one end of our political spectrum, consistently voting for the most liberal candidate available. If it keeps Mr. Alterman up at night to think that our liberals are to the right of liberal Swedes, let that be his white whale.
As they say, read the whole thing.