This should be a required reading on this: The Soviet Union Versus Socialism ( https://chomsky.info/1986____/ )

As a person who was born in USSR and grow up in Russia, I just cant take this seriously. Mr. Kasparov seems to project his own childish fears of "wealth distribution" state which have nothing todo with what Bernie is talking about. Wealth distribution as it was in USSR been tightly coupled with totalitarian rulings by the people in charge. And this is unimaginably far away from what may be happening in states. Three strongly independent branches of power, levels of bureaucracy, and more importantly - civil society which can dictate its free will. I would say that USA is the more than mature country to try socialism and succeed with it.