WASHINGTON – The Republican leader of the United States Senate was asked last week if he believed the Republican president’s denial that his campaign colluded with the foreign power that was trying to help him win.

Mitch McConnell’s answer: “I have no idea.”

His office later said that McConnell misunderstood the question ― that he thought he was being asked if he personally knew whether Trump’s campaign had colluded with Russia. Regardless, McConnell’s four words represent the new president’s problem in a nutshell. Having made falsehoods a staple of his public discourse, Donald Trump now faces enormous hurdles in getting even his presumptive allies to put their names behind his credibility.

That’s just a partial list, and he’s only been in office a month.

“I don’t know if he’s got the internal capacity to change how he communicates,” conceded Ari Fleischer, a former press secretary to President George W. Bush who has generally given Trump a pass on his falsehoods.

This casual, even cheerful use of untruths is nothing new for Trump. As a self-promoting businessman, he actually bragged about his “truthful hyperbole” and repeatedly made false statements under oath in lawsuit depositions. Neither his Republican primary opponents nor Democrat Hillary Clinton was able to make his near-daily falsehoods on the campaign trail enough of a liability to defeat his candidacy.

But with Trump continuing his disregard for facts in the White House, the habit may now become his Achilles’ heel. Multiple investigations in Congress will be exploring the Russian government’s involvement in the presidential election. American intelligence agencies have already concluded that Russian leaders were not only behind the theft of Democratic emails ― which were then released by Russia-aligned WikiLeaks on a near-daily basis in the campaign’s final weeks ― but that they were actively supporting Trump.

For months, Trump claimed that it was impossible to know who had done the hacking, even as he praised Russian President Vladimir Putin as a strong leader. Of late, Trump has claimed that whatever Russia might have done, he personally was not involved.

“Russia is a ruse. I have nothing to do with Russia. Haven’t made a phone call to Russia in years,” Trump said at a news conference last week. “I have nothing to do with Russia. To the best of my knowledge, no person that I deal with does.”

Of course, given his track record with veracity, should Americans take him at face value?

“They should not, because the president and most of his senior advisers are serial liars. It’s that simple,” said Eliot Cohen, a senior State Department official under Bush and a participant of his National Security Council. “I cannot believe a word that comes out of the president’s mouth, the spokesman’s mouth, the vice president’s mouth, because, frankly, he’s morally compromised now, too.”

I cannot believe a word that comes out of the president’s mouth, the spokesman’s mouth, the vice president’s mouth, because, frankly, he’s morally compromised now, too. Eliot Cohen, former National Security Council participant under President George W. Bush

Whether Trump is knowingly lying at any given moment, honestly believing things that are not true or making assertions without caring whether they are true is impossible to know.

Over the course of his decades in the public eye, he clearly has shown the capacity for willful deceit. In the 1990s, for example, he would call gossip columnists under an invented identity to place news items about himself. Once, he called People magazine posing as “John Barron” to claim that his employer ― which is to say, Trump ― was dating Italian model Carla Bruni. (Bruni denied she’d had anything to do with Trump and called him a “lunatic.”)

Other times, he has made suggestions so patently preposterous that it’s difficult to imagine he could have thought them true. During the campaign, he suggested Texas Sen. Ted Cruz’s father had been involved in the assassination of President John F. Kennedy ― and cited a National Enquirer story as his proof.

And for years Trump pushed the conspiracy theory that former President Barack Obama had not been born in the United States, despite clear evidence that he had.

During the presidential campaign, because Trump displayed a lack of knowledge on any number of topics, it was sometimes unclear whether his inaccurate statements about undocumented immigrants “pouring” across the border, increasing murder rates, or trade deficits were intentional falsehoods or simply a function of that ignorance.

In other cases, though, the untruths appeared to be purposeful. Over the period of a few days last summer, for example, Trump falsely claimed that the NFL had sent him a letter complaining about the fall debate schedule (it had not), that the billionaire Koch brothers had tried to meet with him to offer their support (they had not), and that he had seen a video showing hundreds of millions of dollars in cash being unloaded from a plane in Iran (no such video existed).

Trump had the lowest percentage of truthful statements of any recent presidential candidate, according to the fact-checking group PolitiFact. Of the hundreds of Trump claims the group has analyzed since he entered the race in 2015 through his first month in office, a full 70 percent are rated “mostly false,” “false,” or “pants on fire.”

“What can I say? We nominated a fabulist,” one Republican National Committee member told The Huffington Post on condition of anonymity at the time. “There’s no defending that.”

Presidential historians, meanwhile, appeared to form a consensus that Trump’s candidacy was setting a new bar with its falsehoods. “In American history, we’ve never had a major presidential candidate who fabricated facts with the regularity of Donald Trump,” Douglas Brinkley, a history professor at Rice University, said last summer. “He just simply makes up things.”

If Nixon did what he did in today’s context, I don’t think he would have been impeached. Rick Tyler, former aide to Texas Sen. Ted Cruz

Trump has taken that factually challenged approach from the campaign trail directly into the Oval Office. On the first full day of his administration, he claimed the media was underreporting his inaugural crowd of perhaps 1.5 million, even though photos show it was a small fraction of that. He claimed that his audience during a CIA visit had given him repeated standing ovations, even though they were standing when he entered the room and he never gave them leave to sit down. He claimed the news media failed to report on terror attacks, although when the White House produced a list, the attacks had, indeed, been covered ― some of them extensively so.

Perhaps most forcefully, Trump has repeatedly claimed that between 3 million and 5 million “illegal” ballots were cast in the November election, with all of them going to his opponent Clinton. More recently, Trump and his aides have narrowed on New Hampshire, claiming that busloads of Massachusetts residents were taken to the state to vote for Clinton. There is no evidence that any of this occurred. Trump has not offered any, and even New Hampshire Republicans have ridiculed the idea of widespread voter fraud in their state.

Former state party chairman Fergus Cullen tweeted that he would pay $1,000 to anyone who could prove that even a single person had taken a bus from Massachusetts to vote illegally ― and then posted a series of mocking tweets picturing people on buses, supposedly en route to New Hampshire to vote. They included Queen Elizabeth II, Harry Potter and the Partridge Family.

What Trump has succeeded in doing, though, is to have his senior White House staff repeat his various falsehoods on his behalf. Press secretary Sean Spicer was sent out the day after the inauguration to deliver an angry statement claiming that the crowd had been the largest in history. Policy director Stephen Miller appeared on several Sunday morning talk shows to sell a number of Trump untruths, while counselor Kellyanne Conway famously coined the phrase “alternative facts” to describe them.

The net effect, said Cohen and others, is that no one in the White House has retained the role of an honest broker with the American public ― and that lack of trust is going to come back to bite them.

“No matter how clever they think it is to attack the very notion of truth itself, a time will come when they want people to give the president some kind of credit for being truthful when the evidence is not in front of us,” said Cohen, who now teaches at Johns Hopkins University. “That they will not get.”

Brinkley said many Americans are entertained by Trump’s propensity to say outrageous things or exaggerate. “People like tall tales. Some allowances are made, particularly for small things like ‘SNL’ skits or Nordstrom,” he said, referencing two of Trump’s recent tirades. Still, Brinkley said, Trump would pay a heavy price if he cannot earn some credibility.

“Sometimes, he’s going to say something, and he means it, and it is factual, and it’s important, and people aren’t going to believe him,” Brinkley said. “He needs to get his verbal house in order quickly.”

Even Fleischer, who believes that Trump’s main measure of success will be whether he follows through on bringing back manufacturing jobs as he has promised, says Trump has to have Americans beyond his loyal fan base believe him. “He needs those people, he should want those people,” Fleischer said.

Fellow Republican Rick Tyler, a consultant who worked for Cruz during the campaign, wonders how so many in his party have come to accept Trump’s dishonesties as normal.

“It’s a really disturbing and unsettling time when the truth doesn’t seem to matter. If Nixon did what he did in today’s context, I don’t think he would have been impeached. What did he do, break into the DNC and cover it up?” Tyler quipped. “What’s the big deal?”

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