No, free speech rights don’t end at a private property line.
Of course private property rights allow the owner to decide who is on his property.
But the public has a right to an expectation that such rights won’t be enforced with arbitrary arrest and the application of physical force when it comes to what are normally areas which are wide open to the public.
Notre Dame created much confusion in this regard by the extremely liberally biased, ham-handed way they handled these protests.
Are you claiming that the pro-lifers were not warned that any form of pro-life protest on the NDU campus during the Obama visit would be unwelcome by the property owner?