When the policies of the Left are expressed, the most common argument against them, despite their intellectual rigor, is "But that's not the way things are - that won't work because people aren't like that" or some variant.
I don't know if this holds true for the "left" in American politics, but the case with the Lennin, Trotsky and Marx seems to be appropriate. I have read many of their writings. I concur that they were extremely intelligent men. However; the flaw with the communist ideology (apart from the corruption of the central government), was that it denied greed in humans (for lack of a better word). Darwin observed "territorialism" as a trait of all animals... Humans may like to believe that they are above this trait, but I see many fences, walls and other such urine stains in all countries.
Hitler's justification for grabbing absolute power was that "it is better for a million fools to be led by one brilliant man than for one brilliant man to be led by a million fools." Take a few minutes and think about it. This country was founded in direct opposition to the "right of kings". Intellectuals rarely make good politicians for they see the parody of their positions.
For example, when George Bush (Sr.) was in his debates with Ross Perot and Bill Clinton, he couldn't conceal his disgust and disbelief at the kind of crap and audacity that these men were spewing. Given his resume and his long record as a public servant, he knew that the campaign promises of both of his opponents were nonsense - not possible. He came off to the public as "arrogant". Gore did the same thing. Adlai Stephenson (whom Ashton brought up in this thread) was perhaps one of the most brilliant men of the last century in the political arena. But he was unelectable. He tried. 3 times...
People in a democracy don't necessarily feel that intelligence is "the" major factor, based on the last two "two termers" that we've elected. They want an equal part shaman, figurehead (baby kisser)- an actor to play president, someone who makes them "feel good". I don't know that this is necessarily a bad thing either. I still will hear people talk of all the great accomplishments of Reagan and Clinton... Think about it.
In a recent thread, I linked Bill to a short story by Michael Bulgakov, Heart of a Dog written in about '26 but not published in the Soviet Union until '87. I think it does more to explain the proletariat/peasant point of view in Russia than any other material I've read. Since you are interested in Russia and the communist experiment, you may wish to read this for your enjoyment.