Texas is just Texas while Duke has that east cost ivy league feel to it.
If it's going to cost around the same, definitely go with Duke.You would have a much easier time getting a 1L summer job in Texas by going to Duke. Law firms will love seeing that Duke name, rather than the Texas name they always see. Think about it this way: if you go to Texas, you will be competing with the other 450-something Texas 1Ls trying to get a summer job. If you go to Duke and try to get a summer job in Texas, you'll be competing with 5-10 Duke students tops? Furthermore, many value a Duke law degree because of its rareness, so to speak. They don't put out that many students per year, so its an attractive degree. Go with Duke!