President Trump and top Democrats met Tuesday to discuss funding a Mexican border wall. It didn’t go well, ending after nearly 20 exceptionally rancorous minutes.

Afterward, House Minority Leader Nancy Pelosi (D-Calif.) complained about Trump’s behavior. “It’s like a manhood thing for him," she said in a closed-door meeting with Democratic lawmakers, as The Washington Post’s Mike DeBonis reported. "As if manhood could ever be associated with him. This wall thing.”

She may be right. The president often makes decisions that showcase his masculinity and dominance.

He doesn’t apologize or admit he is wrong, even when he clearly is. And he has no problem engaging in name-calling, trashing his “enemies” on social media and at campaign rallies. As first lady Melania Trump said, Trump is a fighter who “will punch back 10 times harder” when he’s attacked. Even before he entered the White House and released records showing that he had high testosterone levels, he bragged about the size of his penis on national television.

He praises strongmen such as Russia’s Vladimir Putin, North Korea’s Kim Jong Un and the Philippines' Rodrigo Duterte for their rash, aggressive and occasionally violent actions. On a phone call last April, Trump praised Duterte, who human rights activists say is responsible for the killings of thousands of citizens struggling with substance abuse, for a job well done.

“I just wanted to congratulate you because I am hearing of the unbelievable job on the drug problem," he said. “Many countries have the problem, we have a problem, but what a great job you are doing, and I just wanted to call and tell you that.”

That machismo isn’t incidental to Trump’s presidency; it’s at the core. In fact, some experts say it’s a big part of the reason he won. Researchers at New York University described it as the “fragile masculinity hypothesis,” or the idea that Trump appealed more to men who are privately insecure about their manhood.

“By supporting tough politicians and policies, men can reassure others (and themselves) of their own manliness," the researchers wrote in a piece for The Washington Post. “For example, sociologist Robb Willer has shown that men whose sense of masculinity was threatened increased their support for aggressive foreign policy.”

That’s reflected in the polls. Trump won 52 percent of the male vote in 2016, according to exit polls. Even now, his approval among men sits at nearly 50 percent, according to Gallup, higher than his overall approval rating. Supporters wear T-shirts that say “Donald Trump: Finally Someone With Balls” to the campaign rallies of the man who spent some time in the professional wrestling ring.

Hip-hop artist Kanye West in effect says it was the president’s stereotypical masculine campaigning that won West’s support. During an October Oval Office meeting, West said, “I love Hillary. I love everyone, right? But the campaign ‘I’m with her’ just didn’t make me feel — as a guy that didn’t get to see my dad all the time — like a guy that could play catch with his son.”

Of course, Trump’s tough-guy energy is a liability, too. It appeals to his base, but just a quarter of voters identify as Republican. And even the number of men backing the GOP and its leader is declining. As Pelosi said, when it comes to the true definition of manhood, Trump simply isn’t it for many voters.