John David Ashcroft was an influential politician who eventually became the nation’s top law enforcement official. After attending Yale University and the University of Chicago Law School, Ashcroft taught business law before embarking on his political career in Missouri as state auditor, state attorney general, governor and U.S. senator. President George W. Bush appointed Ashcroft U.S. Attorney General in 2001, where he remained until health problems forced him to resign in 2005.