T. Keung Hui writes: “Moms for Liberty, the group at the forefront of a national effort to get some books removed from schools, filed nearly 200 challenges in the past week about 20 books it says are too explicit for Wake County (N.C.) school libraries. The school system rejected all the challenges, meaning the books will stay. Wake says the challenges are invalid because they weren’t filed by parents at the individual schools where the books are.”