Prof. Randall Kennedy (Harvard Law) on CNN About Accurately Quoting Racial Epithets
Watch the video here (or here, if that doesn't work). You can also read Prof. Kennedy's open letter to Harvard and Stanford Law School professors which articulates many of the same points; Prof. Kennedy of course has literally written the book on the subject, Nigger: The Strange Career of a Troublesome Word. The CNN exchange, by the way, closes with this:
[Host Michael Smerconish]: … Is the race of the speaker, in the context you've identified, irrelevant?
[Prof. Kennedy]: I think so. If you're making a good point, you're making a good point, whether you're white, black, red, doesn't matter, brown. A good point is a good point. And it would be a terrible thing in American culture if you erected a race line with respect to who can say what.