While I myself was never a liberal, I did notice that even some of my extreme liberal teachers had disagreements.
Some of them were from the pro-maoist camp explaining why China surivived and the soviets didn't, others were from the trotsky ideaology, explaining that if it hadn't been for stalin, and trotsky has survived, that maybe the soviets would have survived, and other groups allegeding that Stalin had it right, and castro was proof of that.
I walked into college right leaning, and walked out hard right wing, convinced that it was government that caused all the problems, and that, in the worst of all worst case scenarios, anarchy by itself was better then marxism.
Ironica a viewpoint as it was, it also helped me make conservative arguements against teachers by hitting them from different viewpoints (i.e. hitting enviornmentalist propaganda with labor propaganda, hitting enviornmentalist propaganda with the race card, hitting the race card with homophobia card...see gentrification, hitting labor with the enviornmentalist stuff, each group can be played against each other).
It also explains George Mitchells famous quote about the democratic party, In any country other then america, the democratic party would be 5 different parties (he is currently the chairman of Disney and the boss of Michael Eisner).
If you ever get a chance to look it up, try and find the articles on the globalization riots, including the one in seattle, you'll see them even attacking each other, especially the anarchists.