The stunning downward spiral of Michael Madigan’s political career ended Friday with a 7 1/2-year prison sentence and a $2.5 million fine for the former Illinois House speaker and the longest-serving legislative leader in U.S. history after he was convicted of trading legislation for the enrichment of his friends and allies. U.S. District Judge John Robert Blakey sentenced the 83-year-old in U.S. District Court in Chicago. Nicknamed the “Velvet Hammer” for his quiet but hard-nosed style, Madigan was convicted in February on 10 of 23 counts in a remarkable corruption trial that lasted four months. The case churned through 60...