This will offend you
So if your idea of spare-time is clutching your pearls, please stay away. Moving on, I think I read the best case for white use of "nigger" in comments. Here's frequent commentr laborlibert:
I like self-loathing Jew as well. In fact, I consider myself a self-loathing Jew, and I'm not even Jewish (I am a Irish/Italian Catholic, although I'm often mistaken for a Jew). I also think the term "Jew-face" is very funny, and I use it to piss off a good friend who is black and Jewish who for some reason only considers herself exclusively black.
But I don't like SLJ nearly as much as I like the word N-gg-r. Don't get me wrong, I don't use it, even in all-white company. But I want to. Not because I hate blacks, or I think its cool or I want to be black, but because its probably the most dynamic and versatile word in the English language. From one sentence to the next, it can be used to express contempt, fraternity, Love, humor, racial identity, racial inclusion (when honorarily conferred on non-blacks), and countless other feelings and attitudes toward the subject. I can't think of any other word that compares and it kind of sucks that I can't include such an effective word in my arsenal. I could put it to great effect even in my profession(for example at a deposition: "Objection to form...N_gg#r").
I give you black folk credit for taking a word loaded with hate, and making it your own.
Labor's case for nigger is basically my own. Frankly, as I've said, I think it's a beautiful, protean, magical word. I love the ATCQ's slur "sucka nigga." I love the retort, "Nigger please." More than that I love, the trivializing disrespect of, "Nigger,what?" I love the fraternity of "Thar's my nigger." I had a buddy whose grandfather used to walk with a cane. But he called the cane his "Nigger-be-cool" stick. because he'd use it as a club, if he had to. My mother used to call brothers who stood on the corner "If I hadda had my gun niggers." She got this from one of my Dad's old Panther buddies who was always talking big about what would have done to some dude who disrespected him if he'd had his gun, "That motherfucker wouldn't have said that if I hadda had my gun." The point was that these were people who lived in this theoretical, coulda, shoulda, woulda world. But to my sixteen year-old ears, "If I hadda had my gun niggers" really came across as something I didn't wanna be. My Moms was a master of deploying language to motivate kids.
Anyway, the point is I love the word, like I love all words. I hate it's overuse, just like I hate the overuse of hot-sauce, sugar or wasabi. But I don't hate wasabi. I basically have decided that the whole "who can and who can't say nigger" should be left to individuals. It's generally true that black people don't like white people using the word, and the case for that is quite obvious--just because my best friend gets to call his wife honey, doesn't mean that I also get to call her honey. They have a particular relationship, based on a shared history. Ditto for blacks.
That said, I've heard anecdotal reports of young blacks and whites--or young blacks and Asians exchanging the word without offense. If that doesn't offend the black people they're using it with, I don't much care. I see no problem with repeating rap lyrics or reporting on something someone said. (People who use say "the n-word" annoy me. We should ban "the n-word" not nigger.) But I'd rather you not use it in reference to me or my folk--unless you're willing to let me call your wife honey.