Why does a campus have the right to “screen”, but not the right to say it won’t allow firearms?
Arms are a Right, education is not.
And most of these schools (Virginia Tech for example) are GOVERNMENT schools.
So you oppose government always requiring people to disarm at court buildings and various major gov complexes?
Government-run or not (and many are state government), each organization/group/etc still has the right of association. That includes e.g., me excluding you from bringing a gun or your smokes in my home. Doesn’t matter you have a natural right to bear arms or smoke; I have a natural right to exclude you or your items on my property.