If USC is privately owned, then you have no inherent “right” to walk on their property. If they choose to rope a section off for a private party that is their right.
Even if this had been a public university Ziegler would have been on shaky legal grounds. For instance, try walking into your mayor’s office uninvited and start claiming that it is “public property”. I don’t think you would get very far and I don’t think you should. In other words, the trustees of the public property have some legal latitude to control use. If they didn’t, how would they keep people from disrupting classes?
I guess you’re right.
The trustees of USC can decide to arrest someone walking on the sidewalk, because that’s equal to walking into the Mayor’s office univited..
If that’s the America you want,
get ready to Be Happy.