Seth Andrews, founder of the charter chain Democracy Prep, created an organization called Democracy Bulders. The latter group of charter advocates issued a report critical of charters that refuse to “backfill,” that is, to accept students who apply after the entry year or other designated points.

Its report showed that this policy means that many charter seats are left empty as the charter sees high attrition.

The target of Democracy Builders’ critique is Eva Moskowitz’s Success Academy. Eva defends her policy of not backfilling, saying it is not fair to her high-performing students to add low-performing students to their classes.

Mike Petrilli supports Eva, saying the point of charters is to free them from regulations.

I thought charters were supposed to be laboratories for innovations that would be shared with public schools? Is it innovative to take in small proportions of English language learners and students with disabilities and to lose those who are problematic? If public schools did that, their scores would soar. But who would educate the kids that no one wants? And what about the idea of equal educational opportunity?