When librarians at local public libraries decide which books to keep and which to exclude, they often violate the public trust by doing so based on ideology. To avoid potential legal liability, these public officials should avoid viewpoint discrimination and suppress their personal biases. Instead, they should select materials that represent the full range of local viewpoints and interests.
School libraries are entirely different. A school library is integral to the curriculum. Therefore, the school and school district must ensure that library materials are consistent with the curriculum and available only to children of appropriate ages. In the case of public schools, this oversight duty extends to city and state governments.
First, what’s not happening: No jurisdiction is actually banning books. Even if a child can no longer get a book in his elementary school, it is often available at the high school or local library, or his parents can order it.