Hmmm. Texas and Indiana both Republican states...so not sure what the bias is.....
Titans are Tennessee, not Texas (they were in Texas as the Oilers, but that was years ago). It ain't political, it's a matter of who is the "annointed one." Peyton Manning is an advertisers wet dream. Steve McNair is perceived as an also ran by NFL bean counters. They want to promote the more marketable commodity.
Manning is a white QB in an overwhelmingly white media market, with national marketing clout. Steve McNair is a black QB in what is perceived as a white media market (Nashville/Tennessee) and so isn't marketable. Donovan McNabb, on the other hand, is a black QB in an acceptable inner city black media market. Makes all the difference in the world.