Hmm, good question.
Without any law school experience, here's my guess about the loitering laws:

If it were a Federal or State, it would probably be unconstitutional, as it would restrict the right of free assembly.
Local or city laws are the the decision of local government, which can restrict as much as the citizenry votes for or against. I don't believe that local laws can be overturned at appeals courts, as state or federal laws can.