Law professor Robert Condlin (Maryland) sent me this video of Stevenson's address about "changing the world" (it starts at about 2 hours and 12 minutes).  It's a very powerful and essentially Christian message, although he never once mentions what would actually be required to change the world.  He does a very good job emphasizing the extraordinary mistreatment of African-Americans in this country, a useful reminder for those who think affirmative action is about "diversity" rather than justice for the victims of world-historic wrongdoing.