As far as I can tell, horseshoe theory is generally true. This is why many people toward the extremes try so hard to deny it.

I've not heard of horseshoe theory: https://soapboxie.com/us-politics/horseshoe-theory-political...

The quick skim I looked at seemed to discuss the word fascism a lot. Perhaps the horseshoe theory is better represented by adding an authoritarian/libertarian axis to the left/right axis: https://en.m.wikipedia.org/wiki/Nolan_Chart https://en.m.wikipedia.org/wiki/The_Political_Compass