The school doesn't have that, but in california "loitering near a school" is illegal and you can go to jail. Even so, how you act in the situation determines the outcome. You have several options, including arguing with the school staff (guaranteed police visit), arguing with the police (likely will make the police less likely to sympathize even if you're not doing something illegal), behaving suspiciously (IE, not making eye contact, not following direct orders from cops, slumping, wearing clothes that cover your face, being a member of a minority that cops believe are prone to being criminal) will get you beaten up, arrested, sent to jail, etc.
How you act in public situations makes all the difference. For example, you could set up in front of the school with a protest sign that says ("Fund police and schools"), you're not going to get the police called on you.