If you believe in so called "public property" such as schools, parks, roads and other areas commonly believed to be owned by "everybody" then there is no person who can claim any more ownership / control over those places than any other person.
If you believe in so called public property, but disagree with my first sentence regarding how public property is administered, then you necessarily believe SOME people have greater rights than others over how the so called public property is to be administered or used. Which is a contradiction in terms and means "public property" is actually administered by the few and not by ALL of the owners. Which negates the idea that the subject property is actually owned by everyone.
If you believe there is such a thing as "private property" then you would accept the idea that there is a person(s) who has the ability to set the terms of what will or will not be allowed on that private property. Otherwise what is the characteristic that makes the property "private" ?
So, where was the NRA shindig held and who had the right to set the terms of what would or would not be allowed there?