This story illustrates much of what is wrong with current education attitudes -- especially in Texas, where bonehead decisions in education can have effects in other states that don't deserve to suffer from a small group's prejudices against apparently 90% of what made modern American society a major force in the world. Texas has a lot of NICE people in it (and I know some of them) and a lot of smart and competent people. Why is it that the nutbars and reactionaries against everything have to make the state look bad?
It's one thing to ban an author because the author's a total dickwad -- that's a perfectly good reason not to spend your money to accommodate their presence. But NOT because you don't like what they write, if what they write is in that field... and even less if you ALREADY INVITED THEM. At that point you're stuck. THEY could choose not to come, but you've committed yourself.
I hope the current firestorm gets through to at least some of the people involved.