At 1:51 p.m. on Jan. 6, a right-wing radio host named Michael D. Brown wrote on Twitter that rioters had breached the United States Capitol — and immediately speculated about who was really to blame. “Antifa or BLM or other insurgents could be doing it disguised as Trump supporters,” Mr. Brown wrote, using shorthand for Black Lives Matter. “Come on, man, have you never heard of psyops?”
Only 13,000 people follow Mr. Brown on Twitter, but his tweet caught the attention of another conservative pundit: Todd Herman, who was guest-hosting Rush Limbaugh’s national radio program. Minutes later, he repeated Mr. Brown’s baseless claim to Mr. Limbaugh’s throngs of listeners: “It’s probably not Trump supporters who would do that. Antifa, BLM, that’s what they do. Right?”
What happened over the next 12 hours illustrated the speed and the scale of a right-wing disinformation machine primed to seize on a lie that served its political interests and quickly spread it as truth to a receptive audience. The weekslong fiction about a stolen election that President Donald J. Trump pushed to his millions of supporters had set the stage for a new and equally false iteration: that left-wing agitators were responsible for the attack on the Capitol.
In fact, the rioters breaking into the citadel of American democracy that day were acolytes of Mr. Trump, intent on stopping Congress from certifying his electoral defeat. Subsequent arrests and investigations have found no evidence that people who identify with antifa, a loose collective of antifascist activists, were involved in the insurrection.
But the false claim has hardened into gospel among hard-line Trump supporters. More than half of Trump voters in a Suffolk University/USA Today poll said that the riot was “mostly an antifa-inspired attack.” At Senate hearings last week focused on the security breakdown at the Capitol, Senator Ron Johnson, a Wisconsin Republican, repeated the falsehood that “fake Trump protesters” fomented the violence.
For those who hoped Mr. Trump’s don’t-believe-your-eyes tactics might fade after his defeat, the mainstreaming of the antifa conspiracy is a sign that truth remains a fungible concept among his most ardent followers. Buoyed by a powerful right-wing media network that had just spent eight weeks advancing Mr. Trump’s baseless claims of voter fraud, pro-Trump Republicans have succeeded in warping their voters’ realities, exhibiting sheer gall as they seek to minimize a violent riot perpetrated by their own supporters.