No, state fairs can’t bar exhibitors from selling or displaying Confederate flag items
The Volokh Conspiracy 2015-08-26
Summary:
Recent news stories report that Indiana and Kentucky state fairs are barring exhibitors from selling or displaying the Confederate battle flag, or products containing that flag; Ohio seems to have done the same, and other fairs are considering it. But such bans violate the First Amendment. Government-run fairs are “limited public fora,” see Heffron v. […]