As a card-carrying member of the Great Right-Wing Conspiracy, I have no use for socialism, but I can see that socialism can work in a small community, where everyone voluntarily joins and remains. Examples are monasteries, convents, communes and such. But even Amish (and similar) religious communities are mainly capitalistic; people work for their own benefit primarily, and contribute to the Whole as directed by the Bishop.
But in a larger context, where people are forced to join, the only way it can "succeed" is with a powerful enforcement structure that demands compliance, and such power will always corrupt those who hold it. See Fidel Castro.
My problem with Americans advocating forms of socialism is that socialism is incompatible with the structure of government created by our Constitution. The Constitution prohibits Congress (the only agency empowered to raise money) from spending money on INDIVIDUAL benefits. It can raise armies, build roads, coin money, and things of GENERAL benefit, but handing out money and valuable stuff to individuals is verboten. And this is intrinsic to socialism.
You may have noticed that Leftists (Democrats) in our current political framework do not recognize this limitation on Congress, and God help us if we were to elect a Democrat in this climate.