Maybe Horowitz is out there providing the outer bounds of what is acceptable in the way of anti-communism.
That is certainly the role that Radosh has played:
Yes, the Rosenbergs were guilty, but Joe McCarthy was bad. Yes the Spanish Civil War was a tragedy, but John Stewart Service was not a Communist agent. And so on. The first is such a throwaway that it's no longer even controversial. The Second is nonsense. The third is a given. And as to the fourth, it's very, very hard to believe that John Stewart Service was merely a simple-minded dupe in the fall of China, which is what Radosh expects us to believe.
Ann Coulter pretty thoroughly demolished Radosh in one of her columns. I guess I take some pity on Radosh. He's an academic and needs to keep his contacts... I guess ...