This weekend, President Trump was mostly up to his usual stuff, popping off on social media, peddling unfounded conspiracy theories to divert attention from stories he doesn't like, and generally acting in an alarming, obnoxious manner. But this particular “Trump rants and rages” story might have lasting significance. According to numerous reports, James Comey, the director of the Federal Bureau of Investigation, has asked the Justice Department to knock down Trump’s new claim that former President Obama ordered Trump’s phones to be wiretapped. Even for Trump, who has been busy rewriting the Presidential etiquette book since the day he was inaugurated, being labelled a liar by a major federal agency would be a first.

The saga began on Friday afternoon. Trump, reportedly furious at how stories about Jeff Sessions’s meetings with the Russian Ambassador had stepped on the good reviews he’d received for his address to Congress, threw a hissy fit at the White House. Then he left town for Mar-a-Lago—his fourth trip to his Florida waterfront resort in five weeks—leaving behind several members of his senior staff, including Reince Priebus, his chief of staff, and Steve Bannon, his chief strategist. Early Saturday morning, presumably from Mar-a-Lago, Trump took to Twitter and declared, “Terrible! Just found out that Obama had my ‘wires tapped’ in Trump Tower just before the victory.” He didn't provide any evidence to back up this claim, but he did say, “This is Nixon/Watergate,” and, in reference to Obama, he added, “Bad (or sick) guy!”

A political media storm ensued. On Saturday afternoon, a spokesman for Obama issued a statement that said, “A cardinal rule of the Obama Administration was that no White House official ever interfered with any independent investigation led by the Department of Justice. As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen. Any suggestion otherwise is simply false.”

On Sunday morning, James Clapper, who had been the director of National Intelligence under Obama, went on NBC's “Meet the Press” and explicitly denied that any part of the national-security apparatus he’d overseen had obtained a court order to wiretap Trump Tower. There “was no such wiretap activity mounted against the President-elect at the time, or as a candidate, or against his campaign,” Clapper said.

Neither of these interventions prevented Trump's conservative allies from ballyhooing the accusations, which appear to have been based on a story that Breitbart, the alt-right news site, published on Friday. (The Breitbart article, in turn, echoed suggestions made by Mark Levin, a conservative radio host, who believes that remnants of the Obama Administration are trying to carry out a “silent coup” against Trump.) Fox News's Sean Hannity tweeted, “What did OBAMA know and when did he know it??” Also on Twitter, Roger Stone, the Republican political consultant and agent provocateur who is also reportedly one of several Trump associates being investigated by the F.B.I. for ties to Russia, said, “The buck stops here. Obama responsible for illegal surveillance of @realDonaldTrump must be charged, convicted and jailed.”

If Trump's media outriders were delighted by his effort to kick up a dust storm, some of his own staffers were less enthused. Reports emerged that certain members of Trump's staff had been blindsided by the boss's eruption. Trump, however, was apparently pleased by the reaction to his tweets. Quoting White House officials, the Washington _Post _reported, “Trump was brighter Sunday morning as he read several newspapers, pleased that his allegations against Obama were the dominant story.” Later Sunday, Sean Spicer, the White House spokesman, issued an official statement that said, “President Donald J. Trump is requesting that as part of their investigation into Russian activity, the congressional intelligence committees exercise their oversight authority to determine whether executive branch investigative powers were abused in 2016.”

As intended, Spicer’s statement produced another wave of headlines. Things didn't stop there, though. On Sunday evening, the Times reported that Comey had asked the Justice Department “to publicly reject” Trump’s assertion that Obama ordered the tapping of his phones—as the Times pointed out, Comey's request amounted to “a remarkable rebuke of a sitting president, putting the nation’s top law enforcement official in the position of questioning Mr. Trump’s truthfulness.”

Trump has learned a couple of things since the start of his Presidential campaign, in 2015. The first is that the media, especially the broadcast media, has an insatiable desire for “news breaks,” even fake ones, and thus is easy to manipulate. The second is that he can say virtually anything, however false or outrageous, without suffering any political consequences with his base. He can call a female journalist a “bimbo,” insult a political opponent's wife, make bogus accusations of widespread voter fraud, say Obama founded ISIS, claim he won a bigger majority in the Electoral College than any President since Reagan—and none of it alienates his core supporters. Arguably, these outbursts make them like him more.

In his tweets this weekend, however, he may, just possibly, have gone too far. Trump has now added his voice to the calls for a proper public investigation into Russia's involvement in the 2016 election. The only way for Congress to properly assess the truth of Trump's claim about Obama would be to call on Comey and other senior officials to provide a full accounting of the interagency investigation into alleged contacts between Russian officials and Trump associates. Is that really what the White House wants?

Much of what we know about the investigation is based on stories citing anonymous sources. But there are some indisputable facts, including the big one—attested to by seventeen U.S. intelligence agencies—that the Russian government was behind the hacking operations that helped the Trump campaign.

Trump, we also know, has long done business with Russians. We know that Trump's former campaign manager, Paul Manafort, worked for years for a pro-Russian political party in Ukraine. We know that, in the run-up to last year's Republican National Convention, Trump associates insisted that the language about Ukraine in the Party platform be softened substantially. And we know that a former British intelligence agent, Christopher Steele, put together an opposition-research document about Trump last year in which he claimed that the “Russian regime has been cultivating, supporting and assisting TRUMP for at least 5 years.”

Details of the actual investigation into Russia’s relationship with the Trump campaign remain murky. In January, a story in the Guardian claimed that “the FBI applied for a warrant from the foreign intelligence surveillance (Fisa) court over the summer in order to monitor four members of the Trump team suspected of irregular contacts with Russian officials. The Fisa court turned down the application asking FBI counter-intelligence investigators to narrow its focus.” The Guardian's report echoed a story published last November by Heat Street, a news site run by Louise Mensch, a former Conservative M.P., which claimed, “the FBI sought, and was granted, a FISA court warrant in October, giving counter-intelligence permission to examine the activities of ‘U.S. persons’ in Donald Trump’s campaign with ties to Russia.”

These unconfirmed stories weren't picked up by major U.S. news organizations, but they appear to have shaped the allegations made by Levin and Breitbart. On Sunday, however, the Washington Post's Glenn Kessler, in a fact-checking piece about Trump's claims, wrote, “The Washington Post for months has sought to confirm this report of a FISA warrant related to the Trump campaign but has been unable to do so.” Clapper, on “Meet the Press,” stated flatly that there was no wiretapping of Trump's campaign, and no application for a FISA warrant to bug Trump Tower.