Zbigniew Brzezinski is a former National Security Advisor, a current professor of foreign policy at John Hopkins University, a scholar at the Center for Strategic and International Studies, and a frequent contributor to Foreign Affairs. He is one of the few national security specialists to have loudly and presciently argued against the invasion of Iraq, and predicted the chaotic aftermath. He is also, if you believe The Politico's reporting, a possible bigot. And because he's one of Barack Obama's foreign policy advisors, Obama may be a bigot too!
Last year, Brzezinski published a qualified defense of Walt and Mearsheimer in a Foreign Affairs article. That was enough to unsettle AIPAC, whose displeasure was made known to reporters, which got the Politico to run a story on Obama's "controversial" choice, which included quotes from Alan Dershowitz sighing, "It is a tremendous mistake for Barack Obama to select as a foreign policy adviser the one person in public life who has chosen to support a bigoted book." The Politico, presumably, would argue that they're just reporting out the controversy, and Dershowitz is merely being quoted. But in general, there's a strategy reporters have when someone lets loose with a batshit crazy smear during an interview: Don't print it.
It is, of course, proof positive of the Israel Lobby's clout, and thus Walt and Mearsheimer's point, that this article exists and these quotes have been printed. That members of the Israel Lobby are attacking the character and positions of Brzezinski in the context of denying his (and Walt and Mearsheimer's) claim that there is a politically influential Israel Lobby that wields great influence and punishes those who diverge from their orthodoxy is almost too bizarre to be believed. It's like telling someone to keep their voice down then having them roar back, "I'M NOT LOUD!"