Why though is a person not entitled to something else? Texas, for example since that is the state we're talking about, used to be part of Mexico, and many people there are of Mexican descent. Why can't somebody get the Mexican flag on their plates? Or the flag of the Spanish Empire? Or even the flag of the United States? A few years ago here in Minnesota, people wanted to have "Pro-Life" license plates. Why not "Pro-Choice," or "Pro-Union?"
If you like it, buy a bumper sticker or paint the stars and bars on the roof of you car a la The Dukes of Hazard.