If the feds were deporting them Texas wouldn't have to do this, but they catch them, turn them over to the feds (as is required) and the feds turn them loose. Would you rather have them on the streets, breaking into homes, stealing cars and selling drugs? They had little choice. All they are "giving" them is the opportunity to better themselves, not giving them an education, allowing the opportunity for them to better themselves if they are willing to pay for it.
Let me try again...
Do colleges receive any government money?
Let them pay the tuition of a foreign student. Which they are. Mexican citizens all.