Bob-

Sure, pure socialism or communism have yet to work in practice, but neither does pre capitalism. We take many things for granted today that would have been condemned as communitst, Marxist, or socialist during the first half of the 20th centruy: mimimum wage, labor unions, child labor laws, welfare, food stamps, and so on and so on. America actually does a pretty decent job at sprinkling just enough socialism into our capitlism to keep the peasants from murdering the wealthy in their sleep.