Seriously this is the most hilarious and silly group -- people from Northern Europe claiming to be against Jews.
Now you got those types who hilariously believe Catholics and Protestants are the same. They're stupid enough (that's another point for discussion). But Nordic anti-Semites. Now those types are hilarious as Hell.
I think most racists didn't belong to the Klan. Stupid ass people.
Non-white anti-Semites (Italians, Spanish [non-Visigoth], Africans, Chinese) are understandible. But white anti-Semites those types are stupid as hell.
It would be an extremely difficult task to Quantify the mean stupidity of a cross section of various racists and fringe groups. Thus, to establish that White anti-semites on average have lower IQ's than other racist groups would be a challenge. It is quite possible and likely that there are groups other than White anti-Semites with lower mean IQ's. Although I acknowledge that any such group would have to be profoundly stupid to meet such a criteria.