Some good points about politics and Texas football being a possible negative.
The biggest area for football recruits is the Texas, AND the South. Florida (being the biggest) specifically has a large disparity of player% in the NFL vs. pop% in the US. Cali has the most NFL football players, but their differential is like 2% whereas Texas and Florida both are 3.28% and 3.77% respectively. Not discounting the other Southern states like Georgia and Louisiana. While I think that is a factor in what jobs you take, it certainly should be no bigger a factor for UT vs. USC jobs.
UT pay the most hands down, bar none. Is that a factor, yes I am sure it could be. If UT offers the highest annual salary and some insane signing bonus (like says 20 million+) they will have a very good chance of getting their pick of the litter. I don't think USC can match dollar for dollar against UT.
I think one thing USC has going for it is fan apathy. Some may find this bad, but the pressure of being the UT coach and winning is second to none. At least in LA if you lose they have the Dodgers, Lakers, Clippers to look forward to. Austin is all about UT football, all year long period. Not to mention having the Longhorn network in bedded in your college program, I also think that is a negative as well.
It does not matter anyways, I think they will make huge overtures to Kevin Sumlin, who I hope says "no", he would never go to UT because that is tantamount to what would be the biggest scandal in Texas football history. Would make for good reading though.