The reason why Brother Carl stopped showing up is actually an exercise in Constitutional law.
One week Brother Carl was doing his usual Pat- Robertson-on-crack rantings, damning everyone and their mother to Hell for whatever non-Republican activity they might be doing. A couple -- who later turn out to be engaged -- walks by, and Brother Carl calls the girl a whore. Her noble betrothed, understandably irked, walked up to Brother Carl and punched him in the face.
Now, you might expect that the assailant in this situation would get in trouble with the law. Actually, the opposite is true thanks to a doctrine handed down in 1942 by the Supreme Court called "fighting words." Briefly, there are some statements which are not protected by the 1st Amendment, words "which by their very utterance inflict injury," and "are no essential part of any exposition of ideas." These are "fighting words" and Brother Carl was guilty of using them. Not only were no charges filed against the young man, but the University had reason to label Brother Carl an instigator of violence and forever ban him from the UNT campus.