In New York City and many other cities, there is a political divide in the public school system. While many liberals support traditional neighborhood schools, conservatives seem to support the charter school movement.
According to New York Magazine, one reason for the political divide is the enforcement of teacher accountability in charter schools:
Moderate liberals and conservatives want to expand and empower the public schools that admit everybody by random lottery. The lefties want to preserve geographic-based restrictions.
A major reason for this is obviously that charter schools are more aggressive about creating accountability standards to promote good teachers and coach up or replace bad ones. This puts them at a crossways with teachers' unions and their allies, which defend paying teachers by seniority and subjecting them to minimal performance accountability.