The DSA has what, 90,000 members?
At that time, America rejected Fascism and chose Socialism, and they prospered for the rest of that century, though by the end the process of dismantling the source of their own success was well along.
https://www.cbo.gov/publication/58888
We already spend a tremendous amount of our GDP on explicitly socialist programs, I don't see any value in framing that as a thing of the past.
We exist in very different realities; mine is informed by the reality I see around me in the physical world, yours apparently exists in links to economics papers. I suspect that we don't have the same day-to-day experience at all.
As to socialism and fascism... I did not say that only the two exist. I did say that one or the other is coming to America. The idea that this is all going to continue indefinitely, in the USA of all places, is absurd. You people hate aristocracies more than just about anything.