We're almost two centuries into the industrial age -- perhaps actually out of it.
When during that period has this approac ever worked? Why would it suddenly start working now?
Attention! There is no 'left' in America.
There's nothing remotely like the Foot/Benn era Labour Party, never mind to the left of that.
Whatever occupies that space in the US -- and it isn't the Democratic Party -- can have their annual party conference in a phone box.
Billy Bob don't care. Billy Bob went to the polls saying "He hates the same people I hate. Hand me the goddamn ballot."
That's how nuanced and sophisticated it was.