I have been thinking about this and here is the conclusion that I have come to just using my own reasoning.
I think the 25/75 percentiles posted in USNWR are a pretty accurate representation of the GPA/LSAT that you need to get into UT as a Texas resident. I don't see how the Texas resident could be significantly lower because at least 80 percent of those reported percentiles are composed of in-state people. Even if we assumed that the top 20% of the class was composed entirely of non-residents and the bottom 80% was composed entirely of Texas residents, the ranges would only be only marginally effected...maybe by a point on the LSAT and a couple of hundredths of a point on the GPA...if even by that much.
In theory, I would think it would be more difficult for out-of-staters to gain admission since basically they are competing with 49 other states for only 20% of the positions in the class. I would think that it would be safe to assume that if you were an non-residents you would have to be on the high end of their score range, but I don't think that it would be a safe bet to say that Texas residents can get in with lower than average scores.
Like I said, these are just my thoughts...