President Donald Trump is not a beacon of truth.
In the best light, Trump was seen as occasionally struggling with the truth. As someone who espoused "truthful hyperbole," Trump's supporters viewed him as a showman who sometimes exaggerated, but ultimately fulfilled his most important promises, such as filling the Supreme Court with conservative judges.
But many took a decidedly darker view. His critics and even a number of supporters say something far more sinister and pervasive was at work -- Trump weaponizing misinformation, or and even lies, to achieve his goals. The president advanced falsehoods on everything from the mundane to what some called the "big lie" -- that the 2020 election was stolen, a repeated assertion that ended in the Capitol siege.
In the current political landscape he nurtured, truth seekers – whether scientists, academics, journalists or intelligence agency officials -- were often attacked, or in some inspector generals' cases, fired, simply because the facts unavoidably collided with the alternate reality created in the White House -- one amplified by Trump's allies in Congress and right-wing media.
The Washington Post Fact Checker's ongoing database of false or misleading claims made by Trump since assuming office stands at more than 30,500.
Dr. Bandy X. Lee, a forensic psychiatrist and author of "Profile of a Nation: Trump's Mind, America's Soul" told ABC News she viewed Trump's "pattern of lying seems to consist of beginning with a conscious lie intended to deceive others -- or to cover up who he really is -- but as more people believe him and the adulations of crowds gratify him in irresistible ways, he comes to believe in his own lies."
"He has adopted almost a practice of preferentially lying over telling the truth," she added. "His grandiose sense of himself, on the other hand, does not allow for any possibility that he is wrong."
Here are four memorable falsehoods from Trump's presidency to show how Trump repeatedly shaded the truth on matters great and small:
TRUMP: The presidential election was 'rigged' and 'stolen.'
TRUTH: Joe Biden legally won the election.
Whether Trump believed it or not, he peddled a conspiracy theory that the election was "stolen" from him and unfairly handed to President-elect Joe Biden. His constant complaint in his final weeks of campaigning was one he had made repeatedly primed his supporters for in the past: the election would be "rigged" against him.
He ramped up "the big lie" after Biden was projected to win the presidency.
Trump and his allies brought at least 60 lawsuits challenging the 2020 elections to date, ending with only a single court victory related to voter ID laws -- which the Pennsylvania Supreme Court later overturned. Former Attorney General Bill Barr also said in December the Justice Department found no evidence of fraud able to overturn the election.
Despite being unable to substantiate his bold claim, Trump made it a topic for debate, and his allies in Congress helped breathe life into the claim. The election lie culminated on Jan. 6, 2021 when thousands of Trump's supporters marched on the Capitol after his urging at a "Save America Rally" at the Ellipse, a park near the White House, demanding Vice President Mike Pence stop Congress from affirming Biden's victory.
"Make no mistake, this election was stolen from me, from you, and from the country," Trump told a crowd of thousands of angry supporters.
The subsequent siege on the Capitol left at least five people dead and burned images into history of a desecrated U.S. Capitol. But experts argue the entire event might have been stopped sooner had Trump admitted the truth to his supporters -- that there was no legal way the election could be overturned in his favor.
Asked whether Trump will ever be able to admit the loss, and thus the lie, Lee, who is also currently president of the World Mental Health Coalition, said, "Probably not."
She said people like Trump have an "apparent fragile sense of self" which makes it difficult to receive criticism or disapproval. "This makes him more likely to fall into a psychotic spiral in the situation of a major rejection, such as election defeat, rather than admit loss," Lee said. "And this is, indeed, what has happened," Lee said.
Robert Erikson, a political science professor at Columbia University, agreed that Trump "makes up the truth that he wants to be true."
"He can never be wrong, and that's why losing is such a blow to him. He convinces himself and everyone else that he really won the election in a landslide. He can't fill in the blanks about how this fraud occurred -- because it's just total lunacy -- but that's what he wants people to believe," Erikson said.
Erikson added that with Trump's departure, the public might see Republican senators revert back to the truth, noting Republican Leader Sen. Mitch McConnell is "already done with Trump" in reportedly telling senators to vote their conscience in the upcoming impeachment trial on an article which stems from the election lie.
"If they don't stand up for the truth, then they're overestimating the power of this base that still wants them to falsely believe the election was stolen," Erikson warned.
The most recent Gallup poll on Trump's favorability found that he is leaving office with his lowest approval rating of his four years in office at 34%. Trump is the only president not to reach 50% approval rating during his time in office, since Gallup started polling the number in 1938.
But despite no evidence to support the view, according to a recent ABC News/Washington Post poll, one out of every three Americans -- and two in every three Republicans -- believes that there was widespread voter fraud in the presidential election, indicating damage on the country's democratic institutions needing repairs far beyond the Capitol's shattered glass.
TRUMP: The coronavirus pandemic is under control.
TRUTH: The US exceeded the White House's 2020 death estimate by 100K lives.
One of the most dangerous lies of Trump's involved the most serious threat to his presidency: his downplaying of the coronavirus pandemic.
Trump admitted to legendary journalist Bob Woodward in a phone call on Feb. 7 he knew the virus was "deadly," airborne, and more serious than "your strenuous flus." Meanwhile, in public and on Twitter, he compared the virus to the seasonal flu and dismissed climbing case numbers.
"I wanted to always play it down. I still like playing it down because I don't want to create a panic," Trump said in a March 19 call with Woodward, according to an audio clip.
Trump, asked by ABC News Chief White House Correspondent Jonathan Karl in September, "Why did you lie to the American people and why should we trust what you have to say now?" dismissed the question.
"That's a terrible question and the phraseology. I didn't lie. What I said is we have to be calm. We can't be panicked." Trump said, before Karl pressed again on the contradiction. "I want to show our country will be fine one way or the other whether we lose one person -- we shouldn't lose any."
Trump also repeatedly spread misinformation about coronavirus testing, masks, unproven treatments -- once claiming that injecting bleach might treat the virus before saying later he was being "sarcastic" -- while attacking public health experts along the way who disputed his view that the virus wasn't just going to "disappear."
"I think Trump understands the facts about how bad COVID is and probably knows masks work, but he is always appealing to his base," said Erikson. "What Trump always does -- and what ordinary politicians do to not do -- is always appealing to his base rather than expanding his base, and the virus didn't fall in line with them."
A year into the crisis, more than 400,000 Americans have died from COVID-19.
TRUMP: 'We had the biggest audience in the history of inaugural speeches.'
TRUTH: Photos from previous inaugurations tell a different story.
The Trump administration kicked off with the lie mocked around the world when Trump used his first full day in office in 2017 to excoriate a media report that estimated the crowd size of his inauguration at 250,000 attendees as a "lie" and instead, to insist he saw at least one million people.
"We had a massive field of people, you saw that. Packed," Trump said in a speech at the Central Intelligence Agency. "I get up this morning, I turn on one of the networks and they show ... an empty field. I said, wait a minute, I made a speech! I looked out, the field was ... it looked like a million, a million-and-a-half people."
Later that day, he dispatched White House press secretary Sean Spicer, in Spicer's first briefing room appearance, to claim "the largest audience to ever witness an inauguration -- period -- both in person and around the globe."
Spicer did not provide evidence and acknowledged the National Park Service in 1995 stopped tallying crowd size on the National Mall. He instead offered varied explanations for why photos made it appear as if the crowd was smaller than the "massive" one Trump pushed. (This was described by then-senior counselor Kellyanne Conway as providing the media with "alternative facts.")
PolitiFact, a nonprofit project operated by the Poynter Institute, estimates Trump's inauguration saw between 250,000 and 600,000 attendees. Nielsen, which records the U.S. live television viewing figures, said an estimated 31 million people tuned in to watch the 2017 inauguration, about 19% lower than the number who watched Obama's 2009 inauguration.
But the lie, made apparent by photos and footage, set the tone for a White House which would come to often contradict fact.
In Trump's first interview as president, presented with his priorities in his first days of office, told ABC News he "won't allow" anyone to "demean me unfairly, because we had a massive crowd of people."
"I looked over that sea of people, and I said to myself, 'wow', and I've seen crowds before. Big, big crowds. That was some crowd," Trump said. "We had the biggest audience in the history of inaugural speeches."
"They were showing pictures that were very unflattering, as unflattering -- from certain angles -- that were taken early and lots of other things," he added, maintaining his position, despite having no clear-cut evidence.
TRUMP: Alabama 'will most likely be hit' from Hurricane Dorian.
TRUTH: Alabama was not in the storm's line, federal officials said.
In Sept. 2019, as Hurricane Dorian barreled toward Florida and Georgia, Trump tweeted that Alabama was one of the states at great risk from the storm's wrath, saying it "will most likely be hit (much) harder than anticipated."
After Alabamians, and beyond, on Twitter went into a frenzy, the National Weather Service office in Birmingham soon tweeted that Alabama was not in the line of the storm.
But Trump, unwilling to admit the error, attempted to prove that his incorrect Alabama tweet was actually correct. After drawing widespread criticism for his inaccurate warning, Trump held up a map in an Oval Office briefing on Dorian that appeared to have a line drawn on it in black making it seem as if he had been right all along.
The event would later be known on social media as "Sharpiegate."
The map Trump displayed had one addition not on the one disseminated by the National Hurricane Center: what appeared to be a drawn-on semicircle appended to the "cone of uncertainty" showing the hurricane's potential projected impact -- extending the cone into Alabama.
Hours after the Wednesday Dorian briefing, Trump denied knowing how or why the map had been altered when asked if he could explain how the change was made, saying. "No, I just know, yeah. I know that Alabama was in the original forecast." White House deputy press secretary Hogan Gidley tweeted Wednesday night that the line was, in fact, from a black Sharpie, and he criticized the media for focusing on it.
Almost a week later, the National Weather Service's parent organization, the National Oceanic and Atmospheric Administration also weighed in, disputing the earlier tweet and siding with Trump in an unsigned statement.
But many experts, including a former director of the National Hurricane Center, took the side of Birmingham forecasters on social media and called the parent statement was "so disappointing," -- illustrating how Trump's falsehoods eroded the credibility of the institutions around him, too.
"Either NOAA Leadership truly agrees with what they posted or they were ordered to do it," Bill Read wrote on Facebook. "If it is the former, the statement shows a lack of understanding of how to use probabilistic forecasts in conjunction with other forecast information. Embarrassing. If it is the latter, the statement shows a lack of courage on their part by not supporting the people in the field who are actually doing the work. Heartbreaking."
As with most of Trump's false or misleading statements, enabled by the power of the presidency and his allies, "Sharpiegate," too, appeared to blow over.
ABC News' Ben Gittleson, Jordyn Phelps and Meg Cunningham contributed to this report.