(REUTERS/Jonathan Ernst)

Donald Trump is the most unusual politician we’ve ever fact-checked, given the sheer volume of his misstatements, falsehoods and unreliable statistics. Trump is on track to earn more Four-Pinocchio ratings by himself than all other Republican politicians (or Democrats) combined in the past three years.

But there is a distinctive pattern to Trump’s biggest fibs. When challenged with irrefutable evidence that his statement is wrong, Trump will grasp at the flimsiest pieces of evidence to insist that he is right, even if the new evidence contradicts or undermines what he had originally claimed. But he will not back down or suggest he might have made even a minor error, creating an illusion for his supporters that his false claim is based on verifiable facts.

Let’s look at three examples, each of which earned Trump Four Pinocchios.

“I was against the Iraq War”

Trump makes this claim to suggest he has good judgment, in contrast to Hillary Clinton, who voted to authorize the 2003 invasion of Iraq when she was a U.S. senator. But no evidence has emerged to back up Trump, and, in fact, his public remarks at the time indicate he was a supporter of the war.

Few appear to remember now, but the reason reporters started to dig for evidence that Trump opposed the war is because he used to claim that he received a visit from nervous White House officials who wanted him to keep quiet.

“I was visited by people from the White House asking me to sort of, could I be silenced because I seem to get a disproportionate amount of publicity. I mean, I was very strong, though: ‘You’re going to destabilize the Middle East,’ ” Trump told Fox News on Oct. 6, 2015. In a GOP primary debate on Sept. 16, Trump made a similar claim: “A delegation was sent to my office to see me because I was so vocal about it.”

So, Trump’s original claim was he was getting tons of publicity with his opposition to the war. But we determined there was no White House visit. That should have been no surprise, given that in a 2000 book, Trump wrote that Iraq had weapons of mass destruction, and, if an attack is needed, “it is madness not to carry the mission to its conclusion.”

Indeed, Trump’s public comments generally were in favor of the war. Asked about whether he was in favor of the invasion, Trump told Howard Stern on Sept. 11, 2002: “Yeah, I guess so. You know, I wish the first time it was done correctly.” On Jan. 28, 2003, he expressed impatience in an interview with Neil Cavuto on Fox News: “Either you attack or you don’t attack.” On March 21, 2003, the day after the invasion, Trump told Fox News: “It looks like a tremendous success from a military standpoint.”

As the gap between Trump’s claim and the reality widened, he dropped the fib that he was visited by a White House delegation and began to rewrite the record of conversations. For instance, he recast the Cavuto interview as showing he was more interested in the economy than the war. He also has started to claim that he privately expressed his opposition to the war in conversations with Sean Hannity and others.

But this is the exact opposite of what Trump asserted from the start — that his opposition to the war was so public and so loud that the White House tried to silence him. Neither version, however, has any credibility.

“Thousands of New Jersey Muslims celebrated the 9/11 attacks”

Trump claimed that he watched thousands of people, in Jersey City, cheering as the World Trade Center towers collapsed. He said he saw it with his own eyes and that “it was well covered at the time.”

This eventually became a problem for Trump: There was no coverage at the time, because the events he described had never happened. There had been rumors that a half-dozen teenagers may have danced in front of a library in South Paterson, but that had never been confirmed.

So what did Trump do? He cited even the tiniest mention of a rumor as evidence he was right. He touted a sentence that appeared in the 15th paragraph of an article that appeared on Page 6 of The Washington Post, saying authorities had questioned “a number of people” who were allegedly seen celebrating the attacks. The Trump campaign also posted snippets of video clips from a local CBS newscast concerning the arrest of eight people after reports they had allegedly celebrated the attacks.

These were scattered reports, and none backed up Trump’s claim of thousands of Muslims celebrating in New Jersey or that it was “widely covered.” It is highly doubtful Trump really remembered–or even read– an inside story in The Washington Post.

Now, it is possible Trump remembered seeing television footage of a group of Palestinians celebrating — images that were in a constant loop on Fox News. That’s what presidential aspirant Ben Carson decided, after first backing up Trump. Carson apologized for “the mistaken references.”

But Trump held firm, claiming the scattered reports backed up his claim, even though all fell far short of his original description of what he saw.

“Hillary started the birther movement”

More than anyone, Trump fanned the flames of the movement that called into question the circumstances of President Obama’s birth. A central part of that claim was that Obama’s birth certificate was a fake and that he was born in Kenya, not Hawaii.

Trump falsely claimed that Obama’s grandmother said she watched his birth in Kenya, that no one knew what hospital Obama was born in, that there are no records showing Obama was born in Hawaii, that Obama did not produce a legitimate copy of his birth certificate and that notices of Obama’s birth in two Hawaiian newspapers were placed as part of an apparent plot to establish he was a U.S. citizen.

Even after Obama released his long-form birth certificate, Trump tweeted constantly after 2011 that he had doubts about the document.

These statements were problematic when Trump suddenly decided this month to declare that Obama was indeed born in the United States. So rather than admit he was wrong, Trump has sought to pin the blame on Hillary Clinton’s 2008 campaign, saying it first raised questions about Obama’s birth. During the first presidential debate on Sept. 26, Trump suggested the 2008 Clinton campaign was “pressing very hard” to find the birth certificate.

Again, Trump grasps at straws to deflect from his own falsehoods. Trump twisted a comment by Clinton’s 2008 campaign manager, Patti Solis Doyle, to suggest the Clinton campaign pressed the birther story during the long battle for the Democratic nomination. Instead, Doyle had reported that a volunteer coordinator in Iowa was fired in December 2007 after forwarding an email perpetuating the birther tale — which is the opposite of what Trump claims.

Trump also seized on a statement by James Asher, formerly of the McClatchy Washington bureau, that during the 2008 campaign longtime Clinton ally Sidney Blumenthal “strongly urged” him to “investigate the exact place of President Obama’s birth, which he suggested was in Kenya.” A McClatchy reporter in Africa determined there was nothing to the claim, and no story was ever printed. Blumenthal, who at the time was not on the campaign payroll, insists that Asher’s claim is false; Asher has not provided notes or other contemporaneous material that would back up his memory.

At best, these instances cited by Trump are wisps of evidence that people loosely connected to the 2008 Clinton campaign were interested in spreading gossip about the circumstances of Obama’s birth. But they pale in comparison to Trump’s repeated questions and statements about Obama’s birth certificate.

Trump has never explained why he touted the birther tale with such fervor, or why he changed his mind after expressing doubts for so long.

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