CHICAGO, IL – SEPTEMBER 17: Striking Chicago public school teachers picket outside of George Westinghouse College Prep high school on September 17, 2012 in Chicago, Illinois. More than 26,000 teachers and support staff walked off of their jobs on September 10 after the Chicago Teachers Union failed to reach an agreement with the city on compensation, benefits and job security. With about 350,000 students, the Chicago school district is the third largest in the United States. (Photo by Scott Olson/Getty Images)