Modern presidents, whatever their party or approach to governing, face the same fate: win the White House, and get on the couch. Presidential temperaments and personalities are exhaustively examined by professionals and lay people alike, as both experts and the public try to figure out what makes the most powerful man in the world tick. Richard Nixon was widely regarded as paranoid, keeping an enemies list. Bill Clinton, his biographers write, had a "hypomanic" personality that included a high-energy, hard-working and creative work style coupled with an impulsiveness and quick temper.

With President Donald Trump, however, the observations of the presidential personality have taken on a more ominous tone. Lawmakers and experts say they are troubled by Trump's extraordinary focus on his own brand and popularity, including frequent and angry insistences that his crowds are bigger and more enthusiastic than anyone else's and that, despite official vote counts to the contrary, he really won the popular vote for president.

The man Hillary Clinton called temperamentally unfit to be president because of his insults of women, Latinos and disabled people has not calmed his demeanor since becoming the 45th president. In a recent interview with ABC, Trump declared he had "the biggest crowd in the history of inaugural speeches," and then showed his interviewer an aerial photo of his inaugural, insisting that other photos clearly indicating a smaller in-person crowd than President Obama's 2009 inaugural were manipulated to demean his own supporters. He said in the same interview that he got a bigger standing ovation in a recent speech at CIA headquarters than star quarterback Peyton Manning got after winning the Super Bowl. And despite having indisputably won the election, Trump declared he could have won the popular vote if only he'd made more visits to states like California and New York, and reiterated his plan to investigate what he said was massive voter fraud in the election, despite a lack of any evidence that such fraud occurred. When Trump was told that he was mischaracterizing a Pew study the president said showed evidence of voter fraud, Trump attacked the study's author, accusing him of now "groveling" – the same word then-candidate Trump used to disparage a disabled reporter in a separate dispute with Trump over facts.

The behavior of the new president in his first week in office has experts and elected officials wondering: is this just a case of a president with predictable quirks, or is it something that raises concerns about Trump's judgment and adherence to factual reality?

John D. Gartner, a practicing psychotherapist who taught psychiatric residents at Johns Hopkins University Medical School, minces as few words as the president in his professional assessment of Trump.

"Donald Trump is dangerously mentally ill and temperamentally incapable of being president," says Gartner, author of "In Search of Bill Clinton: A Psychological Biography." Trump, Gartner says, has "malignant narcissism," which is different from narcissistic personality disorder and which is incurable.

Gartner acknowledges that he has not personally examined Trump, but says it's obvious from Trump's behavior that he meets the diagnostic criteria for the disorder, which include anti-social behavior, sadism, aggressiveness, paranoia and grandiosity. Trump's personality disorder (which includes hypomania) is also displayed through a lack of impulse control and empathy, and "a feeling that people ... don't recognize their greatness.

"We've seen enough public behavior by Donald Trump now that we can make this diagnosis indisputably," says Gartner. His comments run afoul of the so-called Goldwater Rule, the informal term for part of the ethics code of the American Psychiatric Association saying it is wrong to provide a professional opinion of a public figure without examining that person and gaining consent to discuss the evaluation. But Gartner says the Trump case warrants breaking that ethical code.

Trump himself has defended his demeanor as – perhaps paradoxically – the best. "I think I have the best temperament or certainly one of the best temperaments of anybody that's ever run for the office of president. Ever," Trump told a rally of supporters in Colorado Springs during the campaign. And he dismissed questions during the ABC interview about whether he was disturbingly obsessed with his crowd sizes and popularity. Instead, Trump complained that Democratic leaders wrongly revealed that in a private meeting with Capitol Hill leaders earlier in the week, Trump brought up what he said were unfair stories about his inaugural crowd and reiterated the unsubstantiated claim that 3-5 million people voted illegally – and all against him.

On Capitol Hill, Republicans deflect questions about Trump's temperament and his relitigation of a campaign he won. Democrats are alarmed.

"We've moved from the entertainment to the clinical concern. There is a serious clinical concern about, how delusional is this guy?" says Rep. Gerry Connolly, D-Va. "It will only get worse, because this guy is the president and he's surrounded by enablers and sycophants, who instead of trying to call him on it are fueling the delusion. They're enablers," Connolly adds. "They're not stopping the drinking problem. They're handing out the Scotch bottles."

Could it just be a rough transition from Trump's last persona, as a reality TV star? "It's not a show," warns Rep. Jerrold Nadler, a New York Democrat who has known Trump many years because of the New York City connection. "What concerns me is that a man who is convinced of obvious falsehoods, based on some psychological need to believe it – maybe this will occur in something important, too. And then he's [potentially] acting on, taking a position on something that could get us involved in God knows what, based on imagination."

Republicans don't defend Trump's temperament, and when asked, shift the conversation to work on taxes, national security and health care they are eager to complete on Capitol Hill and get signed by the new Republican president – a hope that had been squelched for eight years.

"You know, he has a whole swath of people that I saw were sworn in as his advisers the other day at the White House. That's their job," says Sen. Bob Corker, R-Tenn.

"I think he's hopped on a lot of issues very quickly," says Sen. John Thune, R-S.D., when asked about how Trump's early tenure was going. Sen. John McCain, R-Ariz., who has been one of the more aggressive GOP questioners of Trump and his nominees, is staying out of it. "Long ago, I gave up talking about what the president talks about. I'm concerned about what he does," McCain says, going on to talk about what he hopes to do in the defense and national security arena.

The famously even-keeled Rep. Chuck Fleischmann, R-Tenn., notes diplomatically that Trump is "passionate" and therefore more passionate and "vocal" in his approach to the presidency. "Something that's refreshing about the whole situation is that we didn't see one thing [in the campaign] and get another," Fleischmann says. "Many traditional politicians get elected with one persona and one set of values and rhetoric and then get here and then morph into something else." Not Trump, he says.

Indisputably, Trump's temperament did not hinder his presidential campaign – Democratic strategists, in fact, wonder now if Clinton's focus on Trump's demeanor was a poor strategy. Trump's bombastic rhetoric was seen by his supporters as antiestablishment and disruptive of a failing system in Washington. But there are signs that the public, too, would like Trump to transition to a more measured and dignified approach now that he is president.

A Quinnipiac University poll earlier this month, for example, showed that Trump's popularity had dropped, unusually, during the transition, with the president losing ground on matters such as his perceived intelligence, honesty and leadership. In November, 57 percent said Trump is not "level-headed;" the poll by the Connecticut school in January had the not-level-headed number at 62 percent. Further, by a two-to-one margin, Americans said Trump needs to close his Twitter account, which has served as the president's primary way of rallying his base.

"It worked to his advantage but when people are saying they're fed up with it, maybe it's starting to be a minus," says Tim Malloy, assistant director of the poll.

Some of the hypomanic characteristics Gartner says Trump also possesses are also, paradoxically, the very qualities that "made America great," the psychotherapist says. The creativity, confidence and out-of-the-box thinking, is what has driven the nation's most successful entrepreneurs, says Gartner, who has also authored the book "The Hypomanic Edge: The Link Between (A Little) Craziness and (A Lot of) Success in America."

And since Trump has never held elected office, it's unclear how his personality will manifest as president, as opposed to his previous roles as private sector businessman and reality TV star. "I think once the cabinet members come in, I think that will help him a lot. That will help [things] stabilize," says Rep. Henry Cuellar, a Texas Democrat who nonetheless is concerned about Trump's heavy focus on his popularity. Nadler is deeply concerned about how Trump's personality will work in diplomacy, but says he is glad Gen. James Mattis (whose nickname is "Mad Dog") is Defense Secretary. "Between Trump and [National Security Adviser] Gen. [Mike] Flynn, who also seems off the beam, he may be the only sane guy in the room when important decisions are made. I want him there," Nadler says.