If Jeff Orr is banned from TTU games for using racial slurs, I hope he challenges it in the courts. I think he will lose.
Any organization selling tickets to a sporting event has an obligation to ensure the safety of all those attending the event, especially the players. That said, I believe using racially-charged language to insult players (and spectators) is inflammatory and a threat to the safety of attendees and players.
Freedom of speech is a right that does not include inflammatory speech that could endanger the public, like yelling "Fire!" In a movie theater. I think this is different than standing on a public street corner and uttering offensive/imflammatory speech.