George HW Bush denounced David Duke as an insincere charlatan with a record of nothing but ugly hate, and then he was defeated in his run for a second term by Clinton, a southern Democrat who ran on racist anti immigrant rhetoric. The Republicans have never backed off fierce anti immigrant rhetoric since.
But - hey, okay, fine let the GQP attack nazis for being “national socialists” and let’s see what happens. (Spoiler: they’re not going to do that. And only partly because they don’t know what “national socialism” is)