re: Mississippi should be good at football too.

Ole Miss can be and has been successful at fielding great football teams.

You can be "good" without winning national championships or making BCS bowl games every year.

As for State, this is just a hypothesis, but I think Starkville is the major deterrent. It's kind of a dump, and that's coming from a State fan. :(

Oxford is a beautiful town with quite a bit of non-negative history behind it. I'm sure the party school reputation helps Ole Miss as well :P