Trump first told his lie a month ago. “A wall was put up,” he said, and El Paso “went from being one of the most dangerous cities in the country to one of the safest cities in the country overnight.” Law enforcement data showed that every part of this statement was false: El Paso hadn’t been dangerous, its long-term decline in crime mirrored declines in nonborder cities, and crime in the city didn’t fall—in fact, it leveled off from what had been a trend downward—after a border fence was built there.

Fact-checkers laid out these numbers for the president. He ignored them. In his State of the Union address, he repeated the falsehood. On Monday, after Fox News debunked it, he instructed his fans in El Paso to reject the official figures. “I spoke to people that have been here a long time,” Trump told the crowd. “They said when that wall went up, it’s a whole different ballgame.” Having substituted his alleged anecdotes for data—Trump, the crusader against anonymous quotes, named none of his sources—he then conducted a voice vote to settle the matter. “Is that a correct statement?” he asked, prodding his audience. The crowd cheered.