Perry attacked us.
That was all she wrote.
If anything, I regard Perry's action as revealing of the profound respect he has for the separation and balance of powers in Texas. Don't forget that the in-state tuition bill was passed overwhelmingly by the Texas Legislature, which is also overwhelmingly Republican. There were only four "nay" votes on this bill. It was sent to Perry, and he signed it into law which speaks volumes to me about his respect for the "people's body" the legislature of Texas.
Moreover, this was entirely a state matter: Perry was setting no national precedent here.
Plus I gather he is a very humane man. The son of a tenant farmer, he most likely has had many Hispanic friends, neighbors, and associates in his lifetime, and does not see them as public enemies. Probably most of them were in the country legally. Yet whether legal or no, their children are indubitably residents of the state of Texas. If they had graduated from high school, and been here three years, giving them the same tuition rate as other Texas residents doesn't bother me much especially if this is what the citizens of Texas voted for, through their duly constituted representative bodies.
Plus as a practical matter, a kid getting an education is probably not hanging out in a street gang somewhere, messing around with drugs and other contraband....
I definitely agree with Perry about the utter futility of building a fence. A total waste of taxpayer funds, IMHO. Jeepers, they can always tunnel under it; and I can even envision folks setting up catapults to launch themselves over it. All a fence would do is give us a false sense of security. I'd feel safer with electronic surveillance and boots on the ground.
The most attractive thing about Perry (to me) is he is without doubt a constitutional originalist. He appreciates the role of the several States in the Framers' overall constitutional design. There's an excellent article in the current National Review that you might want to look into for information about Rick Perry's constitutional understandings.