Karen Lewis, president of the Chicago teachers union arrives for a meeting of the union's House of Delegates Friday, Sept. 14, 2012, in Chicago. (AP Photo/Charles Rex Arbogast)

 

              Karen Lewis, president of the Chicago teachers union arrives for a meeting of the union
Karen Lewis, president of the Chicago teachers union arrives for a meeting of the union's House of Delegates Friday, Sept. 14, 2012, in Chicago. (AP Photo/Charles Rex Arbogast)