There hasn’t been a repeat BCS national champion since the BCS era began in 1998. Southern California was voted No. 1 in the final Associated Press poll in 2003, but Saban’s LSU Tigers won the BCS national championship that season. The Trojans came back to win the BCS national title that next season.
The last team to win outright national championships in back-to-back seasons was Nebraska in 1994 and 1995.