I think that history supports Nick A's claim that communism is impossible, although I would say that unsullied democracy is also impossible, and for the same reason. As soon as an institution is set up, be it a political system or religion, those at the top will work to cement their positions and create a gap between themselves and ordinary people.
About, um, 40 years ago or so, I was idealistic and thought communism seemed to be a fairer system. When I said this before a technical college class, a Vietnamese refugee classmate became quite animated in disagreeing and he demonstrated with an illustration on the blackboard. He drew two tall rectangles, as in a bar chart, which indicated that the difference was that, in capitalism you have minority rich, a large middle class and fairly large lower class. In Communism there was a smaller minority of rich and no middle class, just the poor.
In hindsight, I can see it was an exaggerated image, but the thrust of appeared to be correct. There are always gangs at the top controlling, and sometimes oppressing, the rest. This is even the case in tribal societies, where there is inevitably a posse of strong men controlling the tribe. This happens with chimps too.
In the end, we bungle on with the illusion of control, all the time being lead to do what we do by environment, both inter- and extra-societal. We are not free, and we never have been. Rather, Mother Nature leads us by the nose, as she does with all species. It seems to me that humanity's role will be the spreading of the Earth's material to other worlds, where forms (living and non-living) formerly only known on Earth will proliferate around the solar system. Asteroid detection and deflection is also on the agenda.
We like to think that we thought of all these things ourselves, but we are simply responding to environmental exigencies, as does any other species, just that the human ability to perceive the passing of time, remembering the past and projecting into the future at will, empowers them to do things that other animals can't.
But, like other species, one thing we can't do is live in peace. When you have far too many people getting in each others' way and living unsustainably, it's hard to imagine any political system being effective. Perhaps if there appeared a selfless, intelligent, forward-thinking, responsible, honest leader with great communication skills, that could change the situation. Until he or she was assassinated by vested interests, of course.