Nancy Bailey writes here about a zombie policy launched by Jeb Bush called third grade retention. Students who can’t pass a third grade reading test are flunked and held back. Nineteen states have adopted this practice despite a large body of research showing that it hurts kids and leads to future failure, even dropping out. Children who are held back feel humiliated. There is one big benefit to this policy, however. Holding back the kids who have not yet mastered…