New York Times had a map last year that displayed college fans by zip code. In the Houston city limits, Houston was 2nd behind UT in most zones. As you moved out, the Aggies inched ahead of Houston. In the outer zones, LSU did pass UH; nowhere was Tech even listed until you got out west.
I also go back to the survey that was done last year around election time where UH was the 3rd most liked college in the state
Texas leads the state in college sports loyalty with 26% to 16% for Texas A&M, 12% for Houston, 9% for Texas Tech, and 6% each for Baylor and Texas Christian
And if you go back to polls going back to 2011, Tech hasn’t been above UH in any of them and usually competes with TCU for 5th among state schools. Here’s a thread that references those polls: Public Policy Polling Poll shows UH as the 3rd most favorite school in Texas
Tech fans like to think they have a lot of support, but there has been no evidence that they do other than in very sparsely populated counties in West Texas or on College Football forums. Tech fans are also some of the most disliked fans on the internet.