People have the right to peacably assemble. They DO NOT have the right to take up residence in a private park. It is absolutely constitutional to throw these idiots out of the park, and to arrest them if they refuse, and to arrest them if they insist on setting up little socialist communes anywhere else, unless it is on property they own themselves.
For the most part they are peaceful. It appears to me the cops are the first to become unpeaceful...and the protesters are reacting to that.
It strikes me as very dishonest to allow protests except when you don’t like the people doing the protesting.