That doesn't mean all charters are automatically good. They're not. But it's indisputable that the good ones -- most prominently, KIPP -- are onto something. The non-profit company, which now has 125 schools, operates on a model that demands much more of students, parents and teachers than the typical school does. School days are longer, sometimes including Saturday classes. Homework burdens are higher, typically two hours a night. Grading is tougher. Expectations are high, as is the quality of teachers and principals, and so are the results.

KIPP's eighth-grade graduates go to college at twice the national rate for low-income students, according to its own tracking. After three years, scores on math tests rise as if students had four years of schooling, according to an independent study.

The question isn't whether such successful models should be replicated, but how best to do it. In some forward-thinking communities, that reality is altering the stale charter debate.