It’s not like the world hasn’t witnessed plenty of socialism’s horrific failures. From Richard M. Ebeling at aier.org:
It is amazing sometimes how really short humanity’s historical memory can be. Listening to some in American academia and on social media, you would think that socialism was a bright, new, and shiny idea never tried before that promises a beautiful future of peace, love, and bountifulness for all. It is as if a hundred years of socialism-in-practice in a large number of countries around the world had never happened.
If the reality of actual socialism in the 20th century is brought up, many “progressives” and “democratic” socialists respond by insisting that none of these historical episodes were instances of “real” socialism. It was just that the wrong people had been in charge, or it had not been implemented in the right way, or political circumstances had prevented it from getting a “fair chance” of successfully working, or it is all lies or exaggerations about the supposed “bad” or harsh” experiences under these socialist regimes. You cannot blame socialism for there having been a Lenin, or a Stalin, or a Chairman Mao, or a Fidel Castro, or a Kim Il-Sung, or a Pol Pot, or a Hugo Chavez, or . . .
Tyranny, terror, mass murder, and economic stagnation, along with political plunder and privilege for the few at the top of socialist government hierarchies were not indicative of what socialism could be. Just give it one more chance. And, then, another chance, and another.