Rudolph W. Giuliani likens himself to a boxer who never takes a punch without swinging back. As mayor, he made the vengeful roundhouse an instrument of government, clipping anyone who crossed him. In August 1997, James Schillaci, a rough-hewn chauffeur from the Bronx, dialed Mayor Giuliani’s radio program on WABC-AM to complain about a red-light sting run by the police near the Bronx Zoo. ...That morning, police officers appeared on Mr. Schillaci’s doorstep. What are you going to do, Mr. Schillaci asked, arrest me? He was joking, but the officers were not. They slapped on handcuffs and took him to...