He said, he said: Donald Trump and James Comey's accounts differ. Credit:AP In broad strokes, Trump's tweet was accurate. Comey says that Trump tried to convince him to drop the investigation into former national security adviser Michael Flynn; Trump says that he didn't. But Comey also claims to have contemporaneous notes documenting the conversation, which he has provided to special counsel Robert Mueller - notes that shift the balance in Comey's favour. Trump, of course, has hinted that he has recordings of his conversations with Comey - but refuses to confirm whether such recordings exist. (On Friday, he said he would let the world know "in a short period of time" if they do.) Trump's answer to Boyer's question happily accepted the he-said, he-said premise.

US President Donald Trump walks into the State Dining Room of the White House on Thursday. Credit:AP "No collusion. No obstruction. He's a leaker," the President said in his response, tersely summarising what he felt was learned during Comey's testimony. Trump then again claimed that the Russia investigation was just an effort to distract from the Democrats' electoral college loss last year, though the investigation itself began back in July of 2016. "James Comey confirmed a lot of what I said, and a lot of the things that he said just weren't true," Trump continued. Comey testified before the Senate Intelligence Committee last week that he was certain his firing was due to the president's concerns about the Russia probe. Credit:AP That's a significant statement for Trump to make, given that Comey was testifying under oath. If Comey said untrue things under oath - and knew that they were untrue - that's perjury. Trump is accusing Comey of a crime.

But that comment also reinforces another way in which this isn't just a he-said, he-said. Comey was testifying under oath, something that wasn't true of either Trump or his attorney (who released an error-riddled statement about Comey's testimony). ABC's Jonathan Karl asked at the news conference if Trump would be willing to testify under oath about what happened with Comey. "He said those things under oath," Karl said. "Would you be willing to speak under oath to give your version of those events?" "100 per cent," Trump said. (The full response was a little muddled, but this point was unequivocal.) Would he be willing to talk to Mueller, Karl continued, a conversation which would likely require sworn testimony? "I would be glad to tell him exactly what I just told you," Trump replied.

The importance of Trump's unwavering assertion that he would tell the special counsel the same thing under oath is important. Again, Trump's goal is force people to choose who they trust, him or Comey. For those who might be swayed by Comey's under-oath testimony, here's an out: Hey, Trump would be willing to swear under oath, too! But there is a very, very big difference between saying you'd be happy to testify under oath and actually testifying under oath, the same difference as saying you'll give most of your income to charity and actually doing it - something else Trump knows about. Trump knows very well that sworn testimony is a whole different ballgame. Last year, The Washington Post documented a deposition in which Trump was forced to admit to 30 distinct falsehoods he'd made when not under oath. Perhaps Trump will subject himself to the same scrutiny with Mueller, who knows. But until he does, it's premature to give him the benefit of the doubt on honesty. (An aside: The last president to be impeached, Bill Clinton, was tripped up by testimony he gave in a sworn deposition.) Even if it were a he-said, he-said contest with Comey, Trump has far more reasons to be dishonest than does Comey. Trump's presidency is at stake, and if there is a pattern of obstruction of justice in his behaviour - the sort of thing that Comey's testimony could reinforce - the repercussions could be severe. Trump would have Americans believe that Comey is the one lying, motivated by . . . Anger? Revenge? It's not clear.

Trump can lie with literal impunity at this point and has a motive to do so. Comey faces legal repercussions for lying - and it's not really clear why he would. One key reason Trump won the presidency is, again, why he's faring as well as he is when positioned against Comey: partisanship. A Post-ABC poll this week found that more than half the country distrusted Comey, a figure powered by strong skepticism from Republicans. Trump's presidency has been all about playing to his base so far, and his base, in this instance, is returning the favour. It's very possible that Trump is telling the truth, that the conversation didn't go as Comey presented. We should remember, though, that Trump hasn't earnt the benefit of that doubt. In the first 137 days of his presidency, our fact-checkers caught him saying 623 false or misleading things. Even in the story of the boy who cried wolf, most of the time the boy was lying.

Washington Post