Jewish or not, can't be half, neither Kerry nor Weinberger, nor Goldwater are. I believe Max identifies as a secular Jew, I don't know what that is since my education didn't advance to the study of secules. But I think it's fair to say his positions are not influenced to any great extent by Judaism, the religion not the secule thing, and should be viewed as such. He may not like Jews, he certainly doesn't like Israel, and when we focus on his "religion", we confuse that simple fact.
As you probably know I also reject the "self hating" nonsense. Someone may well dislike Jews, but the fact that he's Jewish doesn't mean he hates himself.