So what's the difference? It is this. Some expressions of bigotry are permissible in this country and some aren't.
One had best keep your anti-black racism to yourself — or pretend it's just about Obama as the Limbaughs and right-wingers do. Same with Jews, where, as the Thomas case demonstrates, expressing disdain for Israel, let alone Jews, can be a career killer.
But it's still okay to express open prejudice towards gays and lesbians, Latino immigrants (legal or illegal) and, above all, Muslims and Arabs.
[From Jeff Goldberg Defends Marty Peretz — But Not That Bigot, Helen Thomas]