Probably not in the 2016 election, but the long-term demographic trends (increasing urbanization, increasing migration from "blue" states, a declining white majority) suggest Texas could flip to being a Blue State in the not-too-distant future, at least for presidential elections.
Should that happen, it would add 38-40 electoral votes to the existing "Blue Wall" of states which very reliably go Democratic in presidential elections. The Blue Wall currently holds about 225 electoral votes. Adding Texas to that would put the Blue Wall total to 265 or so. Given that it only takes 270 electoral votes to win, the chances of ***any*** GOP presidential candidate would be virtually nil in a Texas-as-a-Blue-State world.