2002 USC was 12-2, Ohio State was 14-0 and the consensus national champions.
2003 USC deserves to be known as a national champ team as they were undefeated all year #1, but the BCS computers kept them out. But LSU also was the BCS National Champs, therefore I would not call 2003 USC the consensus national champs.
P.S. USC the school doesn't even recognize a 2002 NC, or the '03 and '04.