Andrew Kaczynski of Buzzfeed discovered this little gem of a video, in which then-law student Barack Obama spoke at a protest in favor of Harvard Law Professor Derrick Bell. Kaczynski explains what the protest was all about. Bell was the first black tenured professor at the school, and a pioneer of "critical race theory," which insisted, controversially, on reading issues of race and power into legal scholarship. His protest that spring was occasioned by Harvard's denial of tenure to a black woman professor, Regina Austin, at a time when only three of the law school's professors were black and only...