About that Communism...

Marx's beliefs on the eventual development of the communist state are, to a degree, basic but are they really valid and/or realistic given our history on this earth? The poor get sick of the rich holding power, they overthrow them, then the poor run the show and everyone is happy. Would this really work? Wouldn't there be someone in that group of previously poor people that would want all the power to themselves? Isn't this how most governments were founded? the underdogs take over and create rules and laws and then...they become the powerful and the whole cylce starts over. It appears that the perpetuation of this situation is inevitable and that Marx's idea is more wishful thinking than anyting else.

So, considering the past history of the entire existence of human beings, aren't we just going in a giant circle?