For decades, Illinois House speaker Michael Madigan dominated the state’s political system, corrupting it to his own ends. What should we make of his ouster? The Chicago machine turned out some of the most notorious names in American public corruption, including Anton Cermak, Richard J. Daley, and Ed Kelly. The machine also turned out Mike Madigan, who ruled over Illinois politics for 50 years, 36 of which he spent calling the shots as House speaker. Most people thought Madigan would only leave office in handcuffs or a casket. Most people were wrong. For the first time since 1970, “the Velvet...