Socialism did take hold. It was brutally repressed.

The battle of blair mountain is a clear example of what happens when workers demand fair treatment in America. They didn't just send the army in to break the strike, they sent the air force.

Though they lost, in the long term it raised awareness enough to actually lead to organized labor victories like the New Deal (which effectively led to the creation of the middle class 'good life' from the 50s).

The thing that really worries me is that another, similar battle would be necessary in order to arrest the current decline of the middle class.