Who could have predicted President Trump would react so angrily to being fact-checked by Twitter? The president has threatened to close down social-media companies that “silence conservatives voices,” one day after Twitter added a fact-check label to one of his posts. On Tuesday, Trump tweeted, without providing any evidence, that mail-in ballots would lead to widespread fraud—and Twitter’s new label system merely pointed out that it was an unsubstantiated claim. Clearly infuriated, Trump tweeted Wednesday morning: “Republicans feel that Social Media Platforms totally silence conservatives voices. We will strongly regulate, or close them down, before we can ever allow this to happen. We saw what they attempted to do, and failed, in 2016. We can’t let a more sophisticated version of that happen again.” The president then went on to repeat his baseless claim that mail-in-ballots would lead directly to more voting fraud.