Democratic Socialism devolves into totalitarian Socialism and eventually into full on Communism as people resist statism.
If your political theory requires humanity to "evolve", then you do not have a theory.... you have a dream.
Every totalitarian Communist considered themselves as a Socialist first and foremost.
For 70 years Democrats bitterly denied being "socialists". Bernie Sanders has done the service of exposing them.
Communism is what happens when Socialists realize that they want complete control over every aspect of human life.