President Obama formally announced his nomination to replace retiring Justice John Paul Stevens Monday. Meet Elena Kagan: As an undergraduate at Princeton, Kagan wrote a senior thesis titled "To the Final Conflict: Socialism in New York City, 1900-1933..." Kagan first met fellow radical Barack Obama in 1991, when she became his colleague on the faculty of the University of Chicago Law School after being appointed to an assistant professorship... As dean at Harvard Law, Kagan write to the U.S. Senate, urging that body to kill an amendment that would have protected the White House from lawsuits filed by foreign terrorists...