States are rushing for the No Child Left Behind exit door. Within hours of Education Secretary Arne Duncan’s announcement Monday that he will grant waivers from federal mandates, several states announced that they would apply for relief. Many others are expressing interest, pending the release of more details next month. Tennessee didn’t wait for Mr. Duncan’s news conference: The state sent its waiver request two weeks ago. The mad dash to escape high-stakes testing and gain more flexibility represents “a sense of desperation” among states, said Dan Domenech, executive director of the American Association of School Administrators. “There’s no question...