The Observer actually has this part right:
Things seemed to go sour less than a minute into the interview, but not for any reason that was visible onscreen. Considering that Mr. Alterman can be as smug and arrogant as Mr. Miller, they probably seemed like a great matchup on paper, a kind of minor-league Gore Vidal–Norman Mailer nose-to-nose, a bantamweight bout of self-congratulatory self-confidence. But Mr. Alterman was unusually well-behaved, laying out his arguments on autopilot. Mr. Miller, however, was getting a different read.Miller really did used to be funny. But now his jokes are generaly reduced to excoriating Democrats and towing the party line about the war in Iraq. His one joke about a Republican on his show tonight: Condi Rice can't appear before the 9/11 Commission because she's so smart their brains would burst.
"You look so pissed off," said Mr. Miller.
"What do you mean, I look pissed off?" asked Mr. Alterman.
"I don’t even know what to say. You’re looking at me like—you’re just sitting there." Mr. Miller did an impersonation of what looked like a drunken, mentally disabled guy passing out. "Give me a question and I’ll ask you a question. What do you want to talk about?"
Mr. Alterman laughed nervously.
"Well," he said, "we could talk a little bit more about the way he misled the country." (Meaning George W. Bush.)
Said Mr. Miller: "This is what I’m looking at, here, like this."
He pretended to be asleep.
When Mr. Alterman finished his spiel, Mr. Miller went bolt upright and snapped at the camera: "All right, you’ve been great. Come back anytime."
Mr. Alterman left stunned.
And when a comedian is that consistently partisan, well, the goings get kinda dull for the rest of us.
*"Conducted" meaning "bailed out on" in this context. Also, the caption "Buy an audience lately, Dennis?" beneath the video above refers to the fact that Miller's crew is paying people to be in the audience. Yes, that's right. The original ad has been removed from Craig's List, but you can find it reproduced in a number of places.