Lawrence O'Donnell and prominent blogger Glenn Greenwald engaged in a heated debate on Friday's "Morning Joe" about the political direction the Democratic Party should take in the wake of their midterm election losses.

Two days before he came on the MSNBC show, Greenwald had fired the first salvo in the debate. In a post on Wednesday, he singled out O'Donnell as an example of cable news pundits always advising Democrats to move to the right in order to win elections:

...Almost every time I had MNSBC on [during the coverage of the midterm elections], there was Lawrence O'Donnell trying to blame "the Left" and "liberalism" for the Democrats' political woes. Alan Grayson's loss was proof that outspoken liberalism fails. Blanche Lincoln's loss was the fault of the Left for mounting a serious primary challenge against her. Russ Feingold's defeat proved that voters reject liberalism in favor of conservatism, etc. etc. It sounded as though he was reading from some crusty script jointly prepared in 1995 by The New Republic, Lanny Davis and the DLC.

On Friday, O'Donnell seemed ready to respond. When Greenwald said that the notion that liberalism had suffered a defeat at the ballot box on Tuesday made no sense -- since nearly 95% of the Progressive Caucus in the House had been reelected, while the conservative Blue Dog Democrats had suffered massive losses -- O'Donnell leapt in.

"Glenn, Glenn, Glenn, Glenn, that's the silliest thing you can say," he told Greenwald. The liberal Representatives, he continued, lived in safe districts, whereas the Blue Dogs lived in tight swing districts.

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"Why were you not pointing to the Blue Dogs as proof that conservative Democrats can't get elected when 50% of them disappeared overnight? Why were you pointing to the handful of liberal who lost as proof that liberalism failed?" Greenwald responded.

O'Donnell then pointed to Greenwald's critique of him, saying that there was "not a single quotation mark" showing that he had blamed liberals for the Democrats' congressional losses.

"I asked questions, Glenn," he said. Every single thing you accused me of saying I did not say. I asked questions."

Then, O'Donnell let loose:

"Glenn, unlike you, I am not a progressive. I am not a liberal who is so afraid of the word that I had to change my name to progressive. Liberals amuse me. I am a socialist. I live to the extreme left, the extreme left of you mere liberals, okay? However, I know this about my country. Liberals are 20 percent of the electorate. Conservatives are 41 percent of the electorate, okay?...You can sit there and pretend that liberals should run more liberal in conservative districts. You love the loss of the Blue Dogs. The only way, the only way you have a chairman Barney Frank, there's only one way, that's by electing Blue Dogs. It's the only way. That's the only way you have a Speaker Pelosi."

Greenwald responded to O'Donnell's monologue by calling it "absurd" and saying that, had there been fewer Blue Dogs, the Democrats would have passed better legislation that reduced unemployment, resulting in fewer losses for the Democrats in 2010.

"Insane," O'Donnell replied. "That is insanity!"

The debate got so intense that it had to be continued after the show ended.

Greenwald may have been referring in part to this moment from Tuesday's election coverage, where O'Donnell asked Rachel Maddow about Russ Feingold's loss in Wisconsin: