Why can't I take AP classes?

My AP coordinator (Assistant Principal) is in charge in allowing people to advance in courses. I want to take AP Government and AP English Literature and Composition but they don't think I can do it because they're very tight on who to allow to take AP courses because it reflects in their reputation. I know for a fact that I'll be able to succeed in the class, they don't believe in me, NYU wants AP, this is like being on a cliff, pushing me down is like a big **** you, because then I don't have a good chance at getting into NYU, I need AP, what can I say to the principal?