Trump’s tactics echo those of previous nativist-populist politicians, but his tweets also draw on the contemporary idioms of the alt-right. This is a loose movement, as the researchers Alice Marwick and Rebecca Lewis have written, best understood as “an amalgam of conspiracy theorists, techno-libertarians, white nationalists, Men’s Rights advocates, trolls, anti-feminists, anti-immigration activists, and bored young people” who express “a self-referential culture in which anti-Semitism, occult ties, and Nazi imagery can be explained either as entirely sincere or completely tongue-in-cheek.” Trump is no alt-right digital-news geek, yet his Twitter feed is similarly ambiguous. He seems to provoke his opponents for the pleasure of offending them, but when he is called to account he often claims that he was just joking. Sometimes he promotes conspiracy theories to insult personal nemeses, as he did last week when he tweeted baseless speculation about the MSNBC host Joe Scarborough’s connection to the “unsolved mystery” of an intern’s death.

The President’s tweets slamming CNN, the Times, NBC News, and other media organizations can be comical and weird, but they do serious harm. Last week, a Libyan broadcaster cited one of Trump’s tweets about CNN in an attempt to discredit a report by the network on the persistence of slavery in that country. And, when the leader of a nation previously devoted to the promulgation of press freedom worldwide seeks so colorfully to delegitimize journalism, he inevitably gives cover to foreign despots who threaten reporters in order to protect their own power.