Realism vs. Idealism has nothing to do with it. Liberals like "thugs and totalitarians" who hate America. Liberals hate "thugs and totalitarians" who ally thmeselves with America. If it was a question of being "realistic", they would have backed Mubarek. If it was a question of being "idealistic", they would have backed the Iranian protestors. It has nothing to do with realism or idealism.
Liberals hate the alpha-male and up until a few months ago, America was the world's alpha male.
As long as a man is not in charge, liberals will accept global chaos and nuclear war.