It was billed as the ‘Super Bowl’ of American political events by an eager Washington press corps. Bars and restaurants in the nation’s capital opened early to show the coverage live. James Comey’s appearance before Congress yesterday did not disappoint.

Testifying before the Senate Intelligence Committee, as part of its probe into Russian interference in the 2016 US Presidential election, it marked the former FBI Director’s return to the public spotlight after his sensational firing last month. And right out of the gate, Comey made his feelings perfectly clear.

In a crisp, spare statement befitting a former prosecutor, he set out his "confusion" and "concern" over the Trump administration’s account of his firing. Those reasons had shifted from Comey’s poor handling of Hillary Clinton’s email scandal, to easing the "pressure" of the FBI’s own investigation into Russian interference in the election, as the President reportedly told Russian officials themselves.

But then, Comey said, the administration "chose to defame me and more importantly the FBI" – claiming that Comey had been a poor leader who had lost the confidence of his colleagues. “Those were lies, plain and simple,” he said, his voice cracking with emotion.

"Lies" is a powerful word, made even more so when delivered by the former director of the FBI, about a sitting President of the United States. Even the ranking member of the committee, Senator Mark Warner – a Democrat – wasn’t prepared to use it, referring only to "non-truthful" representations.

But Comey used it again, in even more dramatic fashion. Asked why he had written memos detailing his conversations with the President – reports of which had prompted his appearance before the Committee – Comey explained: "I was honestly concerned he might lie about the nature of our meeting".

The magnitude of that statement takes a while to sink in – not since Richard Nixon have the personal ethics of the President been cast in such doubt, inviting the American public to question what kind of man occupies the Oval Office.

Comey had already set the stage with a written statement, released on Wednesday, that detailed five meetings and phone calls with Trump, painting a disturbing picture of the relationship between the President and the head of a federal agency meant to sit outside the political process.

"I need loyalty, I expect loyalty," Trump told Comey during a private dinner, which Comey saw as an effort to create a "patronage" relationship.

In a phone call, Trump asked the then-FBI director what might be done to "lift the cloud" of the Russia investigation. And most disturbing of all, he cleared the room after an Oval Office meeting to discuss the firing of Mike Flynn – Trump’s former National Security Advisor, who is under criminal investigation by the FBI for his contacts with Russian officials. Flynn was a "good guy", the President told Comey, "I hope you can see your way clear to letting this go…I hope you can let this go".

Republican Senators directed much of their line of questioning to this latter claim by Comey – "hoping" for something was not a command, they said; it wouldn’t stand up in court as clear evidence that the President was trying to obstruct justice (the potential criminal charge lurking beneath this reported incident).

But it’s hard to dispute Comey’s common-sense reading – that in the context of the Oval Office, with all its trappings of power and authority, the President of the United States expressing his "hope" that something might happen is as good as telling you to do it. Comey underscored the point later in his testimony, adding some medieval drama to the whole proceeding. It had struck him much like the famous line attributed to King Henry II, Comey said: "Will no one rid me of this meddlesome priest?"

Another line of questioning – from Republicans and some Democrats – was why Comey hadn’t pushed back? Why hadn’t he told the President it was inappropriate to have these meetings, to make these requests?

Shouldn’t Comey have told someone – beyond the FBI leadership team with whom he had shared his memos? "Maybe if I were stronger, I would have", Comey reflected – referencing the Flynn meeting. "I was so stunned by the conversation that I just took in".

Much of the thrust of Republican questioning on this was to shift the burden of responsibility onto Comey. This was a new President, unclear in his responsibilities and the boundaries of office, they seemed to be saying. It was incumbent upon Comey to inform the White House counsel, who could then school Trump in the behavioural and legal niceties of being President. This was a remarkable position in many respects – not least for the naïveté it ascribes to the President. But it suggests a Republican Party not yet willing to abandon its standard-bearer, on which any prospect of impeachment (another charge lurking underneath all of this) will ultimately turn.

Of course, Comey did not emerge from the hearing entirely unscathed. His admission that he had himself leaked – via an intermediary – information on his memos to the New York Times, gives the President ammunition on one of his favourite topics.

Comey is a now a "leaker" in league with the "fake news" media. Though he managed to restrain himself from tweeting during the hearing, this will undoubtedly feature in Trump’s future pronouncements on the subject. It places Comey’s famed integrity in a somewhat different light, introducing an element of self-interest, attention-seeking, perhaps even "showboating" – as the President has accused him of – into the equation.

This all likely boils down to a "he said-he said" scenario – Trump’s lawyer denies Comey’s version of events (except for an admission that the President himself is not under investigation) and the much-heralded "tapes" of the meetings, which Trump suggested might exist, have not appeared so far. And yet, few would emerge from the hearing without some sense of doubt as to the President’s behaviour.

What Comey describes is a figure more reminiscent of The Godfather than The West Wing – a man using the trappings of office to bully and intimidate, seeking backroom favours and blind obedience from those he considers underlings. The problem, though, is that the American public had a pretty good sense of Trump’s persona in these respects, and elected him anyway. Only if further revelations verge closer to criminality, or go so far as to undermine any basic sense of decency in office, might Trump’s supporters begin to turn away.

Popular support for Nixon ebbed quite slowly during the Watergate scandal (though from a much higher initial point). But doubt and denial played a role – the President’s claim that he was "not a crook" doing little to assure the public. Trump has already shown himself comfortable with a relatively loose relationship with the truth, but his spokeswoman’s statement yesterday – "I can definitely say the President is not a liar" – may well come back to haunt him.

Emily J. Charnock is a Lecturer in American History at the University of Cambridge, and a Fellow of Selwyn College