There are not many cities in the world where the local government puts on a house-music festival—and even fewer where it would be as delightful as the one held in Chicago over the first weekend of June. On a sunny Sunday people of all races and ages filed into Millennium Park downtown, many clutching blankets, coolers and camp chairs. One attendee, however, was clearly not welcome. At sunset the headliner, Farley “Jackmaster” Funk, a storied Chicago DJ, invited on a special guest. As Brandon Johnson, the mayor, jogged onto the stage, a chorus of boos rang out. Within 45 seconds he had left, his seemingly truncated message that Chicago is “the greatest frickin’ city in the world” not enough to silence the din of dissent.