I strongly disagree with your assertion that the KKK is Rightism. The KKK was established as the paramilitary wing of Democrats, and they have no place in the American Right.
The political terms "right" and "left" originated in eighteenth century France and didn't spread outside its borders until the early twentieth century. And the original "right" was not dedicated to free enterprise. As a matter of fact, American palaeo/libertarian hero Frederic Bastiat was considered a leftist in his day and sat in the same part of the French legislature as the other leftists, including socialists.
The original Ku-Klux Klan and the one that has existed in some form or another since December 1915 are not related and have very little in common. The former was the "resistance" to "carpetbag" rule in the Reconstruction South; the latter was something else altogether. The original Klan was not anti-Jewish or anti-Catholic, or even explicitly chrstian and didn't even burn crosses. For some reason everyone seems to identify the two as one.
The twentieth century Klan did indeed have progressive tendencies, but I doubt it was ever intended to be the paramilitary wing of the Democrat party.