Hispanics still vote predominately Democrat, even in Texas. But the difference has gotten much smaller than it was 5-10 years ago. And this is no accident. Again, Hispanics tend to be culturally conservative, and they are are natural source of GOP votes. But you must either cultivate this source or risk losing it to the Democrats. The last thing I want to see is Texas turning into another California.
I think the "hispanics" you are talking about have spanish last names but otherwise think of themselves as Americans. Many have been here hundreds of years, many more have generations who've fought and/or served in uniform. The folks pouring in from the PAN provinces don't fit the demographic you are talking about. Build the wall; put an end to chain immigration.