Brussels, meanwhile, retains the progressive faith in managing democratic outcomes by regulating what can and can’t be said. Mark Zuckerberg’s dismissal of Facebook’s fact-checkers and his replacement of them with a “community notes” approach pioneered by Elon Musk at X (formerly Twitter) signals the end of an aberrant era in American politics that began shortly after the first election of Donald Trump in 2016. The era of trying to manage American political outcomes by having social...