If the US government hadn't just completed a program of left-wing eradication in the early part of the 20c, the pressure probably would have turned rural people towards the populism that they had turned to throughout the 19c and very early 20c; the kind of populism that culminated in the 4-term FDR presidency and the New Deal.

"Populism" as you use it here (to refer to right-wing antisemitic groups), was intentionally turned into a slur that was used to attack the working-class left-wing:

> Most of the Progressives, such as Theodore Roosevelt, Robert La Follette, and Woodrow Wilson, were bitter enemies of the Populists. In American political rhetoric, "populist" was originally associated with the Populist Party and related left-wing movements, but beginning in the 1950s it began to take on a more generic meaning, describing any anti-establishment movement regardless of its position on the left–right political spectrum.

https://en.wikipedia.org/wiki/People's_Party_(United_States)

https://en.wikipedia.org/wiki/Eustace_Mullins

-----

edit: as far as I can tell, the only two things that are characteristic across all European cultures are drinking cow's milk and conspiracist antisemitism. Although America further developed it and fed it back to Europe (note Ford's influence on Hitler), the framework is definitely European. And of course, a lot of fascism in Europe was financed by the US post-WWII.