A former federal prosecutor, Lightfoot won 74 percent of the vote with almost all precincts counted compared to 26 percent for Preckwinkle, a long-time local fighter, to become Chicago’s 56th mayor. Lightfoot, 56, who can also become the first openly gay mayor of this third-largest U.S. city, appealed to voters that are tired of politics as normal. You made a movement for change,” Lightfoot told hundreds of fans at her election night party, promising to end corruption and create the city’s streets safe again.