As near as I can get the facts, they go approximately and briefly like this: Brian Leiter is a colleague (that is, at the same university) and buddy of John Mearsheimer, of The Israel Lobby fame (or infamy). Mearsheimer wrote a positive blurb for an unpleasantly bizarre little book called The Wandering Who by a Brit named Gilad Atzmon. The book, inter alia (and there are plenty of alia), implies that we should not entirely reject the blood libel against Jews in the Middle Ages. The blood libel, of course, is the claim that Jews kill or killed Gentile children to mix their blood with matzos at Passover.
Mearsheimer was strongly criticized (one should hope so!) for writing the blurb but refused to back down from it. Leiter leaped to Mearsheimer's defense without, it appears, doing his homework very well. In the course of that defense of Mearsheimer he implied that Atzmon is not an anti-semite and that therefore the criticisms of Mearsheimer for endorsing Atzmon are hysterical right-wing smears. This defense of Mearsheimer and, in the course of it, defense of Atzmon, resulted in Leiter's being named by Alan Dershowitz in the above article as someone who is helping to make anti-semitism acceptable in the mainstream.
Now, please remember, I just started looking into this very recently, with even less motivation than Leiter should have had for being very careful. I wanted to be fair though, so, though I didn't want to read the whole of The Wandering Who, I did find a couple of Gilad Atzmon's own defenses of his book, including what he calls his "deconstruction" of Alan Dershowitz's criticisms. See here and here.
And guess what? Atzmon really does endorse at least a provisional acceptance of the blood libel. He says,
Anyway, [Dershowitz is] certainly not impressed by my idea that children should be allowed to question “how the teacher could know that these accusations of Jews making Matza out of young Goyim’s blood were indeed empty or groundless” (185). I suppose that Dershowitz hasn’t heard about Israeli professor Ariel Toaff’s study of Jewish medieval blood libel. Toaff found that accusations of blood rituals levelled against Jews in the Middle Ages were not entirely without foundation, to say the least.Sweet, huh?
This exceedingly telling "defense" by Atzmon appeared on November 9, and Leiter's defense of Mearsheimer for endorsing Atzmon's book appeared on September 26. So Leiter didn't have access, presumably, to Atzmon's own further gloss on the passage in his book. But what Atzmon says here makes it clear that those who took him to be, shall we say, trying to open minds about the truth of the blood libel by portraying Jewish educators as stifling free inquiry were understanding him completely correctly! (Atzmon's story was about how he as a child raised a question about whether the blood libel was justified and about how he was sent home as a punishment for being so bold as to step outside of usual Jewish thought. His point in telling the story, now, billing his childhood self as the persecuted hero of epistemic honesty, is not terribly obscure.)
Now, just to complicate matters a tiny tad, Atzmon turns out to be, or at least finds it convenient to present himself as, some sort of postmodern historical skeptic. He says,
Dershowitz sure has some chutzpah, since it’s actually he who didn’t read ‘The Wandering Who’. If he had, he would have seen that in the book and in all my writing I neither deny nor do I affirm any historical aspect of the Holocaust, gas chambers or the Judeocide in general. Instead, I insist that history cannot be sealed by laws. I also insist that intellectual curiosity and our knowledge of the past cannot be vetted or confined by anyone, let alone such morbid minds as that of Dershowitz himself.and
I actually urge my readers to question every historical narrative and this obviously includes the Shoa and Jewish history.This allows Atzmon to be a Holocaust-denier with (im)plausible deniability. He can encourage people to be skeptical about the occurrence of the Holocaust as an "historical narrative," but when he wants to defend himself, he can fall back (as he does in the interview Leiter read--see below) on talking like the Holocaust did happen. He can also point out that he's treating the Holocaust like he treats all history. Nifty, huh? It's amazing what postmodernism can do for all manner of nastiness, including anti-semitism.
When Leiter hastened to the defense of Mearsheimer, he didn't apparently check into the allegations about Atzmon in any detail whatsoever. He seems to have based his evaluation of Atzmon on an interview (a fawning interview published at Atzmon's own site) in which Atzmon maunders on about the Holocaust in pseudo-academic terminology that downplays the true nature of his views. (Whaddaya know, it doesn't look like the little matter of the blood libel comes up in that interview.) From this Leiter infers that Atzmon is probably not an anti-semite.
Now, how can I put this tactfully? That's careless. If I had a colleague accused of enthusiastically endorsing a disgusting piece of anti-semitic trash, with the specific accusation that the tract in question promotes the blood libel, I'd try to do a leetle more research than Prof. Leiter appears to have done before rushing off and publishing something on the Internet calling the criticisms of my colleague "right-wing smears."
But maybe that's just me.