The most obvious place would be the ideology of the Nazis. We're told they were in some sense right wing or "far right" and thus must be more extreme versions of the Republicans. The primary historical sources don't show that. They show the National Socialists running on an ultra-left wing platform as you'd expect, they called each other comrade, and the Nazis grew by converting communists and other far leftists. There is even a speech where Hitler says he welcomed the Bolsheviks into the party and that the Nazis were almost all left wing people in the early years, because he needed people who would beat up their enemies. It's in one of the table talks I think.