I grew up in Corinth. My family still lives there and I can tell you that this feels pretty accurate now when I visit. It's an even 50/50 before the sidewalk fans.
Pre-Jackie, it was pretty heavily pro-Rebel. Until high school, I always felt like I was in the minority.
Also, you can tell the sidewalk fans in North Mississippi, because today they claim Bama and Auburn, but if they took this poll in the 80's and 90's, the answer would have been Tennessee or one of the Florida schools.
I can also vouch for the Texas/Texas A&M split in Dallas-Fort Worth and the surrounding areas. For a lot of these idiots, Texas is the default and then it's a split between A&M, OU, and TCU. I was a little surprised to see Houston go so heavy for Texas, though. A lot of the A&M fans around here (my wife and in-laws included) feel like Houston is an A&M stronghold.