EV, you are missing the point: A private property owner gets to decide who is trespassing and who is not.
Under the logic you are using,
a pro-life private property owner
can’t keep
pro-abortion demonstrators
off of his private property
during
a pro-life demonstration.
The cure you suggest is far worse than the disease.
The campus is open twenty four hours a day. If you went to South Bend right now you could walk anywhere you wanted on the grounds, unimpeded.
At the time in question, supporters of Obama were allowed to continue to do so, with signs or whatever.
Anti-Obama protesters were treated differently, based on nothing more than the content of their speech.