At Fox Business Network’s debate in North Charleston, S.C., candidates vied for momentum ahead of the Iowa Caucus. Washington Post reporter Robert Costa names the winners and losers from that night. (Dalton Bennett/The Washington Post)

It was one of the most memorable moments of the night: Donald Trump defended his “New York values” with a calm, forceful, deeply personal reflection on what it was like to be a New Yorker after the 9/11 attacks.

That moment showed just how far Trump has come as a candidate, revealing a style that was more purposeful statesman than bombastic showman. When Sen. Ted Cruz (R-Tex.) questioned the New Yorker’s values, Trump could have fired back with a nasty takedown of Cruz’s Texas values. Instead, Trump explained himself and his city.

“When the World Trade Center came down, I saw something that no place on Earth could have handled more beautifully, more humanely than New York,” Trump said to warm applause, forcing Cruz to also clap. “The people in New York fought and fought and fought, and we saw more death, and even the smell of death — nobody understood it. And it was with us for months, the smell, the air. And we rebuilt downtown Manhattan, and everybody in the world watched, and everybody in the world loved New York and loved New Yorkers.”

The delivery was polished and rather poetic. For a candidate famous for his off-the-cuff remarks, it was deliberate and purposeful, perhaps even rehearsed. And unlike so many of Trump’s previous comments on 9/11, this one did not contain any distracting exaggerations or wild inaccuracies.

The crowd cheered — even though some of them had booed him earlier in the evening. Twitter lit up with positive reviews, and actress Mia Farrow posted the iconic photo of a U.S. flag being raised at Ground Zero with the hashtag, #NewYorkValues. New York-based political pundits later praised Trump for his defense of their town.

Donald Trump uses repetition as a tactic when he speaks publicly, because it drives home his points. (Peter Stevenson/The Washington Post)

In that moment, the billionaire reality television star became more human — and perhaps even likeable to those who had their doubts about him.

Trump has said that it has taken him a while to learn how to debate, as he’s a New York businessman, not a politician. While Thursday night’s debate still featured Trump’s biting insults, obsessive recitations of poll numbers and artful twisting of facts, the candidate seemed to be making an effort to seriously explain why his controversial stances are resonating with Republicans not privileged enough to get a seat in the debate audience.

In the audience that night was South Carolina Gov. Nikki Haley (R), who used her rebuttal to President Obama’s State of the Union address earlier this week as an opportunity to make a veiled attack on Trump: “During anxious times, it can be tempting to follow the siren call of the angriest voices. We must resist that temptation.”

Rather than responding with defensive rage, Trump called Haley “a close friend” and said she was right: He is angry.

“I’m very angry, because our country is being run horribly, and I will gladly accept the mantle of anger,” Trump said during the debate. “Our military is a disaster. Our health care is a horror show: Obamacare. We have no borders. Our vets are being treated horribly. Illegal immigration is beyond belief. Our country is being run by incompetent people. And yes, I am angry.”

Speaking in the spin room after the Fox Business GOP debate on Jan. 14, Donald Trump continued his attacks against Ted Cruz. (Dalton Bennett/The Washington Post)

Debates are one of the few times Trump is forced to publicly explain himself before a live audience that’s not packed with his supporters. In the past few months, he has slowly limited his exposure to difficult questions asked in uncontrolled environments. He picks and chooses which journalists are granted interviews and rarely takes questions from reporters on the campaign trail. And he doesn’t allow random Iowans to publicly grill him on his positions in diners, pizza shops or other places that have long been the backdrop of presidential primaries, instead opting for massive rallies where his ideas are endorsed by the roar of a crowd.

On Thursday night, Trump was forced to defend his call for a temporary ban on allowing most foreign Muslims entry to the United States, a proposal that former Florida governor Jeb Bush said was “rash” and sends the wrong message to the rest of the world.

Trump tried to walk-back a statement that he made to the New York Times editorial board about wanting to impose a tariff of up to 45 percent on Chinese goods, accusing the newspaper of being “always wrong” but maintaining that China has been ripping off the United States for too long.

And Trump had to explain why he’s questioning Cruz’s eligibility to be president, as Cruz was born in Canada to a U.S. mother and a Cuban father.

That question prompted the crowd to laugh at Trump. Cruz joined in and said “there is nothing to this birther issue” other than Trump reacting to his poll numbers “falling in Iowa.”

Trump responded by correcting Cruz on those poll numbers: “Headline: Trump way up, Cruz going down.” The crowd booed, but he kept going and said there are “very, very fine constitutional attorneys, that feel that because he was not born on the land, he cannot run for office.” He warned that the Democrats could sue over this question. He likely didn’t win anyone over, but he planted the seeds of doubt.

“There’s a big question mark on your head, and you can’t do that to the party,” Trump said of Cruz’s eligibility. “You really can’t. You can’t do that to the party. You have to have certainty. Even if it was a one percent chance.”

Trump focused his closing remarks on the recently released photos of U.S. Navy sailors who entered Iranian waters earlier this week and had their boats seized. Trump said he was with a group of construction workers when the “terrible” photos were released.

“They’re tough, they’re strong, they’re great people — half of them had tears pouring down their face,” Trump said. “They were watching the humiliation of our young 10 sailors.”

After the debate ended, the cameras remained on Trump as the voices of pundits began analyzing and picking winners. As other candidates chatted with one another, Trump wandered around the stage until his family joined him. His super-model wife was at his side, but it was his oldest daughter, Ivanka, now visibly pregnant, whom he engaged for his first extensive post-debate conversation. Cellphones came out as the family grouped together for rounds of photos, with Trump often flashing a double thumbs-up.

The photos were then inspected, compared and sometimes retaken — that subtle routine well-known to families of all sorts across the country.