Some sort of Great Depression? And then I assume the downswing after was catalyzed by the miserable failure of socialism in the context of the USSR, PRC, Cuba, and other countries. Combined with the astonishing associated death tolls, I'm guessing that took the shine off the ideology. Plus it's harder to sell people on one extreme without another extreme like fascism to play off of. IMO that's why extremists are always so focused on moderates; opposing extremists justify and enhance extremism, but the existence of moderates threatens their attempts to frame matters in purely Manichean terms.
Funnily enough, we are once again faced with a choice between rational socialism of the kind that was implemented in the USA in the 1930s, or fascism of the kind that was implemented in various other places in the 1930s.
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.
You make it sound like we don't already spend trillions each year on a network of social programs, as though that somehow stopped instead of endlessly expanding. You also make it sound like only socialism and fascism exist, as though moderate views aren't even in the mix, despite that being where most people have always been.
This being ycombinator, before I would attempt to get on the same page with you, I would need to know your income level and how much time you spend walking on sidewalks without bodyguards.
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.
And after the 1940s after defeating Fascism, America entered a cold war with the USSR/Communists. The capitalists prospered the rest of the century and the Communists after looking good in the immediate aftermath of WW2 had stunted growth before eventually collapsing in the 90s