Comey also dismissed Trump's claim that he was wiretapped by his predecessor during the campaign, a sensational but unfounded accusation. Credit:Bloomberg "I have no information that supports those tweets," Comey said of a March 4 twitterstorm in which Trump levelled the wiretapping charge at Obama, "[and] we've looked carefully inside the FBI." And before any of the panel could argue that he spoke only for the FBI, Comey added that he had been asked by the Justice Department, which does much of the legal work to approve surveillance operations, to inform the committee that it too had no such information. The FBI boss didn't actually utter the word, but he pretty well called his President a liar. Trump's fake news claims are bumped aside by a more disturbing reality: Americans are led by a President whose own intelligence agencies are investigating foreign intervention in the election by which he came to office, and whether or not his campaign was complicit.

FBI Director James Comey, left, and National Security Agency Director Michael Rogers testify on Capitol Hill. Credit:AP Comey's was the latest in a series of authoritative rejections of Trump's wiretapping allegation – some from his own Republican Party colleagues. But despite calls from a couple of Republicans for him to apologise to Obama, Trump has talked up his charge while, at the same time, qualifying it. White House spokesman Sean Spicer claimed, at one stage, that Trump had put quote marks on the word wiretap in the tweet, which should have conveyed that it was a shorthand for a range of surveillance techniques. FBI Director James Comey pauses as he testifies on Capitol Hill in Washington on Monday. Credit:AP But the bigger story here is the Kremlin's intervention, which the US intelligence agencies have concluded was a deliberate bid by Moscow to give Trump a leg-up.

As Trump lunges from one outrageous tweet to the next, it's not only foreigners who scratch their heads while wondering about an absence of accountability. From left: House Intelligence Committee member Terri Sewell questions James Comey, as Jim Himes and Adam Schiff listen. Credit:AP "On paper we have limits on power," Chris Edelson, a scholar on government at American University, told Fairfax Media, "but it's not automatic. And the reason it's not working is because Republicans in Congress are not asking questions. "Right now we don't have a fully-functioning constitutional democracy. The courts and state governments can do some of the work, but it's really difficult when Congress doesn't hold to its oversight role." A sign outside a rally for US President Donald Trump at the Kentucky Exposition Centre in Louisville on Monday. Credit:Bloomberg

There was evidence of that in Monday's hearing. In the course of more than five hours of questioning, GOP members were fixated more on running to ground those responsible for leaks that embarrass Trump than they were about getting to the bottom of Russian interference in the 2016 presidential election. And along the way, this remarkable 21st-century moment: while members of Congress grill intelligence chiefs, the President, hunkered at the White House, is tweeting his take on their testimony in real time, and congressmen are reading Trump's tweets back to the intel chiefs to see if they agree. Connecticut Democrat Jim Himes read a tweet in which Trump claimed that Comey and Rogers had testified "that Russia did not influence electoral process" – an issue dear to the President's heart because it affirms his legitimacy. Comey: "I haven't been following anybody on Twitter while I've been sitting here." Himes: "This tweet has gone out to millions of Americans, 16.1million to be exact – is that accurate?"

Comey: "We've offered no opinion, have no view ... on potential impact, because it's not something that we've looked at ... It certainly wasn't our intention to say that today because we don't have any information on that subject. And it wasn't something that was looked at." Comey testified jointly with National Security Agency director Michael Rogers, and both officials warned that Russian meddling was likely to be a feature of future election campaigns. "They'll be back in 2020. They may be back in 2018," Comey said. "One of the lessons they may draw from this is that they were successful, introducing chaos and discord [to the campaign]. It's possible they're misreading that as 'it worked, so we'll come back and hit them again in 2020'." With some analysts speculating that the FBI's Russia inquiry could hang over the Trump White House for years rather than months, a new reality appears to be dawning on Republicans. Pleading for Comey to release as soon as possible information that might clear a half-dozen Trump associates who have been named in media reports, Intelligence Committee Chairman and Trump loyalist Devin Nunes identified a dark reality after just two months of the 45th President's tenure:

"There's a big grey cloud that you've now put over people who have very important work to do to lead this country, and so the faster that you can get to the bottom of this, it's going to be better for all Americans," he said.