I don’t know if he agrees with them. I have no problem denouncing communists, Nazis, skin heads, or any other group of haters. If my writings were appearing in their publications, I’d make damn sure everyone knew I had nothing in common with them. Is that too much to ask? If you associate with people (as he appears to do), why would it be my responsibility to save his reputation? Surely, that’s his job. Maybe then the “coincidence” that his foreign policy is anti-Zionist wouldn’t seem like it was animated by some baser instincts. He’d just be anti-Israel because he’s a man of principle. After all, it’s not in the constitution that we’ll help Israel.
I see no reason to indulge them with the publicity. That would be counterproductive, IMHO.