Well given that this scenario hasn't happened and is unlikely to ever happen, I doubt that any of us have "instant knowledge" of the results in such a scenario.
Your assumption is entirely unrealistic. Would Rice lose a point or so because she is black, yes. Would Rice gain a point or so because she is black, yes. Rice would do fine in MS, AL, GA, NC, TN, VA, FL, and SC. The only places I'd be concerned about are LA and AR and I'm concerned about those places anyway.
Just because you live in the South doesn't give you instant knowledge of the results in this scenario. Understand, I'm not trying to call the entire South racist, or anything stupid like that. I know a lot of people in Oregon that probably wouldn't vote for a black woman. I'm just trying to be realistic about the outcome.