A GOP function for its members is about as private as you can get. Would John Edwards free speech have been denied to him if they didnt allow him to speak?
Public = Government, all else is private.
It is funded by party donations, all the party. If you enjoy
serving a titular king, then have a ball.
I think that Fisher was misguided on the "free speech" sign, but NC GOP party bylaws more than likely state that the party cannot prefer a candidate in a contested GOP primary election.
By excluding the other candidates from the event and giving preferential treatment to Dole on just about everything, the NC GOP may have broken their own bylaws prohibiting endorsing a candidate in a constested GOP primary.