Shortly after 10 a.m. on day 2 of the Great School Strike of 2012, the long stretch of Western Avenue in front of Lane Tech was blanketed in red. More than 100 striking teachers at the elite North Side high school, all wearing the official color of the Chicago Teachers Union, paraded up and down the street, clanging cowbells and chanting, “Hey, hey, ho, ho! Rahm Emanuel’s got to go!” Cars and every CTA bus, police car, and garbage truck that passed honked in support.
Stranding some 350,000 students, the September walkout was the first teachers’ strike in the Chicago Public Schools, the country’s third-largest school district, since 1987. It cast a national spotlight on the influential reform movement that is bent on reshaping American public schools—and the dogged efforts of the Chicago Teachers Union and its little-known first-term president, Karen Lewis, to resist it...