By resisting almost any change aimed at improving our public schools, teachers unions have become a ripe target for reformers across the ideological spectrum. Even Hollywood, famously sympathetic to organized labor, has turned on unions with the documentary "Waiting for 'Superman'" (2010) and a feature film, "Won't Back Down," to be released later this year. But perhaps most damaging to the unions' credibility is their position on sexual misconduct involving teachers and students in New York schools, which is even causing union members to begin to lose faith.

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