Socialism in the US has its roots going way back in the 19th Century. Authors like Emerson long embraced extremist socialist ideas, which even then were destructive, hateful insanity. By the time of the Civil War, socialism offered things like a justification of slavery, and feudal rule by the 10% of elites over the 90% of everyone else.
Of course any objective analysis of their claptrap showed that it was worthless, but this did not deter them in the slightest.
The big schism in socialism began just before the turn of the 20th Century in both Europe and the US, in the latter called “progressivism”. In Europe the split was between the National Socialists (fascists) and the Socialist-Communists.
In the US, nationalist socialists embraced Teddy Roosevelt, and internationalist socialists embraced Woodrow Wilson.
It should be mentioned that in the US, both the far left and right were minorities in their respective political parties, the vast majority of centrists not supporting either philosophy.
With the utter failure of Russian communism under Lenin, progressive leftists in the US did try developing fascist economic ideas in the great depression, but they were almost as bad as the communist ideas.
Yet the vast conservative center remains, with no interest in the failed 19th Century philosophies of socialist progressivism.
Excellent summation.