Follow @lynnsweetWASHINGTON — NBC News anchor Lester Holt moderates the first presidential debate Monday between Hillary Clinton and Donald Trump, and how — and whether — he fact-checks during the showdown will be a factor in the outcome.

The faceoff at Hofstra University in Hempstead, New York, is expected to draw a giant audience on a variety of televised and social media platforms, including Twitter, which is getting into the act with a new debate livestream.

Clinton, a veteran of high-stakes debates, needs to convince viewers she is likable and trustworthy.

Trump, a master of live reality television, has to come across as temperamentally fit and qualified to be president.

Clinton, who is recovering from pneumonia, is cramming with a seasoned team of Democratic debate specialists.

Trump, the slacker student, is gambling that voters won’t care if he comes to Hofstra up to speed on the issues Clinton has mastered.

“You have to do something in the first five minutes of the first debate that says, ‘I hear you, I get it, I’m not completely who you think I am,’ ” political consultant and news analyst Frank Luntz says.

OPINION

Follow @lynnsweetThe utter unpredictability of Trump, the billionaire reality show star who doesn’t care whether what he says is true, has made the Hofstra debate more of a challenge for the Clinton camp to game.

Trump steamrolled his Republican rivals in a series of primary debates with quips and insults that were simple yet powerful statements. With a crowded field, Trump had the ability to pick his shots and just stay quiet when the debate discussion turned to policies and issues about which he wasn’t well-informed.

He won’t have that luxury at Hofstra.

In an email titled “Trump debate preparation survey,” Trump’s team asked people, “Do you think Trump should refer to ‘Crooked Hillary’ on stage?”

Holt and the format

Trump and Clinton will stand behind lecterns for the 90-minute debate. Holt selected three amorphous topics — “America’s Direction, Achieving Prosperity and Securing America” — giving himself latitude to ask just about anything.

The protests in Charlotte, North Carolina, and the attacks in New York, New Jersey and Minnesota are likely to come up even if Holt doesn’t ask about them — same for the Trump and Clinton foundations.

Holt lived in Chicago when he was at WBBM-TV for 14 years, beginning in the mid-1980s. He will face a unique dilemma for presidential debate moderators: How to deal with Trump, who is highly likely to say things throughout the night that are not true and to make claims that have been discredited.

NBC’s Matt Lauer earned poor reviews for not calling out Trump during the recent “Commander-In-Chief” forum. And CNN’s Candy Crowley was criticized after a 2012 debate during which she had tried to fact-check Mitt Romney.

The Commission on Presidential Debates, the bipartisan organization sponsoring the debates, leans toward moderators staying out of the fray. A top Clinton adviser said Friday that approach gives Trump an unfair advantage.

“The role of the moderator is to challenge the candidates to challenge each other,” says Mike McCurry, the co-chair of the Commission on Presidential Debates. “And if one candidate says something demonstratively untrue, then the opponent is the one expected to respond to that.

“If that does not happen for some reason, then the moderator has the prerogative to step in and ask for clarification,” says McCurry, who was a White House press secretary for President Bill Clinton.

Clinton communications director Jennifer Palmieri held a conference call with reporters on Friday to discuss the Clinton team’s “concern” about Trump’s “record of lying and what that means for how the debate may unfold.”

While Clinton “has a responsibility to defend herself and she will,” particularly when it comes to her own record, the burden of letting the audience know when what Trump has said is not true “cannot be only on her,” Palmieri said.

Palmieri wants Holt “to call out those lies and to do so in real time.”

Regarding reports that Trump has been devising ways to get under Clinton’s skin, Palmieri brushed that away with a “good luck.”

Clinton has far more experience at being badgered under pressure than Trump — and not just at debates. Last October, she took incoming for 11 hours from hostile Republicans at a House Benghazi hearing.

Still, a debate performance is sometimes cemented by an exchange lasting a few seconds. At a GOP primary debate, Trump deftly replied when told former Mexico President Vicente Fox said Mexico would not pay for his border wall.

“The wall just got 10 feet higher,” Trump snapped back.

The other commission co-chair, Frank Fahrenkopf Jr., is a former Republican National Committee chair. Hofstra is the first of three presidential debates.

Expectations

Trump seems headed to getting extra points if he shows he can stay composed for 90 minutes — a very low bar.

Sean Spicer, the Republican National Committee chief strategist who is advising the Trump campaign, is among those trying to lower expectations of Trump.

“The pressure is squarely” on Clinton “to live up to her reputation as a talented debater,” Spicer wrote in a briefing memo.

Trump is merely a “successful businessman. Few are expecting the same level of polish from a verbal gunslinger whose rhetorical strength is speaking to the heart — and the gut — of the American people,” Spicer wrote.

Former Democratic adviser Chris Lehane helped prep Al Gore for debates in 2000 and was part of Bill Clinton’s 1996 debate team.

Hillary Clinton has been debating since her 2000 Senate campaign. In previous debates, Lehane says, she “has done very well when she has been the counterpuncher. . . . She picks her places where to counterpunch to make a point.”

Says Lehane, now the global head of policy at Airbnb: “What [voters] are really looking for is a broader takeaway about the character and the personality of the two candidates. It’s incredibly important for each candidate to have a theory of the case of what they are trying to accomplish.”

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