The richest man in Illinois does not often give speeches. But on a warm spring day two years ago, Kenneth C. Griffin, the billionaire founder of one of the world’s largest hedge funds, rose before a black-tie dinner of the Economic Club of Chicago to deliver an urgent plea to the city’s elite. They had stood silently, Mr. Griffin told them, as politicians spent too much and drove businesses and jobs from the state. They had refused to help those who would take on the reigning powers in the Illinois Capitol. “It is time for us to do something,” he...