Donald Trump, the serial liar who will be sworn in as President of the United States next week, lied once again on Monday, rejecting the actress Meryl Streep’s condemnation of him for impersonating a reporter’s physical disability on the campaign trail last year by insisting that he had done no such thing.

“For the 100th time,” Trump wrote on Twitter, “I never ‘mocked’ a disabled reporter (would never do that) but simply showed him… ‘groveling’ when he totally changed a 16 year old story that he had written in order to make me look bad.”

Trump’s Twitter spats and false claims are by now so routine that it can seem pointless to even report them, but this one is worth unpacking, because it reveals a cascade of lies leading back to a false claim that helped him win: the fantasy that Arab-Americans in New Jersey had openly celebrated the September 11, 2001 attack on the World Trade Center as it took place.

Trump has indeed insisted dozens of times since November, 2015, that his public mimicry of the reporter, Serge Kovaleski, a veteran New York newspaperman who has arthrogryposis, a congenital condition that limits his ability to move his joints, was not an impersonation of his physical disability.

The fact that Trump introduced his impression of Kovaleski by saying, “the poor guy, you got to see this guy,” and then held his right arm in the very position — raised, with the wrist locked so that his hand pointed down — the reporter’s colleagues are familiar with, convinced many people who know him that the then-candidate had, consciously or not, improvised a physical impersonation of the man.

Trump’s subsequent claims that he had no idea what Kovaleski looked like were unconvincing, given that the reporter had previously spent enough time with the businessman for one of the New York tabloids he pays so much attention to, the Daily News, that they were on a first-name basis.

<> at the Algonquin Hotel on April 21, 2010 in New York City.

Serge Kovaleski, left, a veteran New York newspaperman who has arthrogryposis, a congenital condition that limits his ability to move his joints, in 2010.

Photo by Neilson Barnard/Getty Images

What made Streep’s criticism of Trump’s mimicry in her speech at the Golden Globes on Sunday night so effective was that she evaluated it as a performance — one that, she said, “stunned me; it sank its hooks in my heart, not because it was good, there was nothing good about it, but it was effective and it did its job: it made its intended audience laugh, and show their teeth.”

While Trump continues to deny that his imitation of Kovaleski that day, as part of an insult-comic style attack on his credibility, included any intentional mimicry of the reporter’s disability, it is possible that the physical impersonation was unconscious.

To be charitable, Trump could be engaging in what Dan Kahan, a psychologist at Yale University, calls “identity-protective cognition.” That is, as Maria Konnikova explained in The New Yorker, a description of how people tend to “process information in a way that protects their idea of themselves. Incongruous information is discarded, and supporting information is eagerly retained. Our memory actually ends up skewed: we are better able to process and recall the facts that we are motivated to process and recall, while conveniently forgetting those that we would prefer weren’t true.”

What’s important for us to recall, however, is that, apart from the offensiveness of his impersonation, Trump was at the time also lying to his audience about Kovaleski’s reporting.

The reporter’s work, and persona, only made its way into Trump’s stump speech in late 2015 because the candidate was attempting to argue that an article Kovaleski wrote in 2001 backed his false claim to have watched live television images on Sept. 11, 2001, of “thousands and thousands” of Arabs in New Jersey “cheering” as “the World Trade Center came tumbling down.”

In what was, briefly, a central concern of the Republican primary campaign, Trump refused to retract that false claim, continuing to insist that he had seen such scenes that day even after it became apparent that there was simply no footage, for the good reason that televised mass celebrations had not taken place.

Trump, desperate for any scrap of evidence that might keep him from being branded an outright liar, then began to cling to a sentence in a story Kovaleski wrote one week after the attacks for the Washington Post. In that article, Kovaleski had referred to the fact that a few people were arrested for allegedly celebrating the attacks (although none were subsequently charged and there was no video).

(As it happens, five men of Middle Eastern appearance who were arrested in New Jersey that day for “puzzling behavior,” mistakenly interpreted as joy, were later released without charge; they were Israelis, not Arabs.)

Kovaleski, however, undermined Trump’s spin by telling the Post’s Fact-Checker, Glenn Kessler, that, although his memory of the story was not perfect, “I certainly do not remember anyone saying that thousands or even hundreds of people were celebrating.”

Trump, thus exposed, then invented his wild mischaracterization of the reporter’s comments as “groveling” in which Kovaleski had supposedly “changed” what he had written in 2001, as part of an intentional effort “to make me look bad.”

That, to this day, is how Trump attempts to explain what led him to offer a mocking impersonation of a reporter whose only crime was to deny that his careful reporting of the facts in any way supported an ugly fantasy about the supposed disloyalty of Arab-Americans plucked from the internet by the next president of the United States.

Top Photo: Donald Trump onstage at the Republican National Convention on July 18, 2016 in Cleveland.