I'm a little confused by the claim that
'nigger' is racist in a special way because it's an assertion that all black people come from a certain location. If that were the case, a conversation like this would make sense:

A: "Don't forget John, he's a nigger too."
B: "That's not true- he's from Uganda."

Right now, both 'nigger' and 'Paki' offend some people and communities for the exact same reason- they refer to a group (people with black skin, ethnically Pakistani people- or is it South Asian in general?) and they convey or assume negative sentiment about that group. It is totally unnecessary to know anything about the history of either word to be offended or not offended by it.

What it will take for either of them to not be offensive is probably exactly the same- for that negative sentiment to be bleached from the meaning of the word, which tends to happen when the social conditions that the word is used in change. Like 'paddy wagon', 'gyp', 'fag' (maybe on its way there), in American English. I'm not confident with Br. English examples, but I bet there are some good ones. :)
( the prick of misery pierced my foot on a spiiiike on, Tue 21 Aug 2012, 18:31, 1 reply)

Tell a Scot he's English and get back to me.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 22 Aug 2012, 9:01, closed)

Shut up Pykey!

(Misery McUglywife an attention seeking sociopathic fuckstain., Thu 23 Aug 2012, 6:20, closed)