It’s an interesting problem for charter-school afficianados: many want charters to have all the freedom of private schools, but go to pains to let people know that charters are public schools whenever the schools are under fire (or want money). Well I’ve just learned — perhaps before reporters have even been able to write their stories, because I haven’t yet found a news link to it — that New York’s Public Employee Relations Board will force the KIPP AMP charter school in New York City to let its teachers unionize.

This will be a tough pill for KIPP AMP to swallow, especially since an integral part of the famous KIPP model is requiring employees to be available far beyond the normal working hours of traditional public school teachers — not something the United Federation of Teachers is known for loving. But this is the chance you take when you run a charter school: No matter how much you want to act like a private school, sooner or later the public-schooling powers will remind you of what you really are.