Professor chooses professor. That s one headline you could write about Barack Obama s nomination of Elena Kagan to the Supreme Court. Obama graduated from Harvard Law School in 1991, Kagan in 1986. Kagan joined the faculty at the University of Chicago Law School in 1991 and became a full professor there in 1995. Obama taught constitutional law there, though he was not formally a professor, from 1992 to 2004.