Blackface is not a fighting word.
Also, the burden would not be on the person being prosecuted to prove anything. It would be on the party trying to bring charges against them. Innocent until proven guilty. It would be the burden of the offended party to prove that this infringed on their rights. And it must be a VERY persuasive argument, as courts are very remiss to limit anyone's speech. It's not an impossible argument, but it would be very difficult, and would cost a good deal of money to litigate.
They should be punished. Absolutely. But the only people who can adequately do that is the GLO, which is a private organization that doesn't receive gov't funding. The school can't do much if it receives any gov't funding (which there are VERY few institutions that do not)- not to mention that the school can't really afford to deal with more lawsuits than necesary.
A quick search of GA federal and state cases reveals none that mention blackface. In cases outside of that jurisdiction, blackface is generally considered as nonverbal speech protected by the first amendment. That's just from a quick scan of Lexis.
For people who are really interested in this kind of subject, i'd really suggest seeing if your school offers a Freedom of Speech class.... during undergrad, it was offered through my school's communications department. There are also many constitutional based classes in poli sci and history departments. Or if you really want to put yourself through hell, go to law school
