There's certainly a Radical Left position on the political spectrum. But I wouldn't say that it has much of a foothold in America. A few ratbags in universities, perhaps.
If you mean the Democrats, they are about as far left as the Girl Guides.
I suppose you consider Bernie Sanders to be a radical socialist, whereas the truth is that his views are about as middle of the road as you can get.
America as a whole is skewed so far right compared to the rest of the Western
World it just sounds hilarious to hear you.
Trust me, there's not a lot of danger that America is going to develop forced urban collectives under the swinging corpses of the billionaires any time soon.
America has a lot of problems, but the danger of a socialist revolution isn't one of them. You can put your feet up and stow that particular worry at the back of the garage of your mind.