WASHINGTON — When President Trump is battling a man, he tends to belittle his foe with nicknames like “Cryin’ Chuck” and “Low-energy Jeb.” When he is in a fight with a woman, he is known to lob insults like “horseface” and “ugly” and “dog.”
But Mr. Trump has never before faced an adversary like Speaker Nancy Pelosi.
Their latest clash, over the State of the Union address, ended with the president capitulating late Wednesday night, and agreeing to delay the speech until the government shutdown is over. Earlier in the day, Mr. Trump tried to back Ms. Pelosi into a corner by saying he intended to give the speech next Tuesday in the Capitol. She called his bluff and disinvited him.
For a president who prides himself on being a master negotiator, Ms. Pelosi is a different kind of opponent, and one who so far has flummoxed him.
Longtime friends of the president say Mr. Trump is not afraid of powerful women, respects them and has empowered them at the White House and in his business. But on the rare occasion when he was challenged by a woman, Mr. Trump was either in charge — or knew the woman had a boss, usually a man, to whom he could appeal, said Barbara A. Res, a former executive vice president of the Trump Organization.
In this case, Ms. Pelosi is her own boss. And under the Constitution, she is a leader of a branch of government that is equal to the chief executive.
“Dealing with anyone with power equal to his is a first for him — at least in his mind,” Ms. Res said. “He has the perception that he is the most powerful person in the world, and then he comes up against somebody who thinks they have as much power as he or as much control as he, and that’s a shock to him. And it’s complicated by the fact that she is a woman.”
Unlike Hillary Clinton, Ms. Pelosi is not running a race against the president and she is not going away. She also has an understanding of the way the legislative branch works that he does not. Most important, she is blocking him from getting something he desperately wants: a wall along the southern border with Mexico that was a core promise of his 2016 campaign.
“I think that he’s caught between his respect for Pelosi and his anger at her resistance,” said Michael D’Antonio, the author of “The Truth About Trump.” “He gets very frustrated when he can’t close a sale. And I think that he’s perplexed about how to get what he wants here because he respects Pelosi.”
The president went so far as to acknowledge Ms. Pelosi’s powers on Wednesday in a takedown of Senator Chuck Schumer, Democrat of New York, in what Democrats saw as a bit of projection. “I think that Chuck Schumer sadly is dominated by the radical left and he’s dominated by Nancy Pelosi, very strongly dominated,” Mr. Trump said. “He can’t move, he’s a puppet, he’s a puppet for Nancy Pelosi, if you can believe that.”
(Mr. Schumer has proved an adept negotiator in his own right, provoking the president to claim ownership of the shutdown during an Oval Office meeting in December.)
In one sense, the row over the State of the Union reveals as much about the difficulty Mr. Trump is having adjusting to life in Washington under a divided government as it does about his treatment of women. When Paul D. Ryan, a Republican, was speaker, Mr. Trump could exert leverage over Mr. Ryan, just as he can over Senator Mitch McConnell, the Republican leader. He cannot do that with Ms. Pelosi.
Gwenda Blair, another Trump biographer, said Mr. Trump typically viewed women as “easier targets” in negotiating sessions. But that is not the case for Ms. Pelosi. For starters, the only nickname he has devised for Ms. Pelosi is her own name — Nancy.
“Nancy Pelosi, or Nancy, as I call her, doesn’t want to hear the truth,” the president told reporters Wednesday at the White House — a comment that was either meant to showcase a supposedly close relationship or, alternately, diminish her by dropping her last name. But if it was an attack, it was by Trump standards unusually restrained. (Before the election, Mr. Trump tried calling Ms. Pelosi “High Tax, High Crime Nancy Pelosi” on Twitter, but it did not stick.)
“He knows how to emasculate men and he assumes that will work, and he knows how to attempt to shame women around their appearance, but he doesn’t have a useful weapon in this relationship,” Mr. D’Antonio said. “He has yet to give her a nickname, he has yet to criticize her appearance and I think he knows that would be very risky for him to do. So I think he’s stuck in a way that he’s rarely stuck.”
John Feehery, a Republican strategist who advised former Speaker J. Dennis Hastert, sees something else at work: smart politics. He said Mr. Trump treated Ms. Pelosi respectfully for a very simple reason: He respects her.
“Compared to how he treats everybody else, I think he’s been very respectful and I think that’s good politics for him,” Mr. Feehery said, adding: “You have to be careful when you’re trying to deal with the speaker. She’s got power. You don’t want to unnecessarily insult her because that’s not good politics and I don’t think it gets him a better deal.”
The speaker, for her part, has used Mr. Trump’s playbook against him. After their much-publicized Oval Office meeting, she described his demand for a wall as “like a manhood thing for him” during a private session with Democrats. The comment quickly leaked out. At other times she has cast Mr. Trump as a toddler.
“A temper tantrum by the president,” Ms. Pelosi said this month, describing Mr. Trump’s conduct during the shutdown. “I’m a mother of five, grandmother of nine. I know a temper tantrum when I see one.”
Ms. Pelosi, who is often the only woman at the negotiating table with Mr. Trump, has not been shy about correcting him. The first time he hosted her at the White House, he asserted — without evidence — that he had won the 2016 popular vote because three million to five million people had voted illegally, Ms. Pelosi told MSNBC at the time. “I said that’s just not true,” she recalled telling him.
When Mr. Trump tried to undercut Ms. Pelosi during the Oval Office session last month by suggesting she was constrained because she was facing a challenge in her bid to become speaker, she cut him off.
“Don’t characterize the strength that I bring to this meeting as the leader of the House Democrats,” she told him, in a moment that quickly went viral.
Ms. Pelosi’s allies have been celebrating.
During a closed-door meeting of Democrats, Representative James E. Clyburn of South Carolina, the No. 3. Democrat, introduced Ms. Pelosi by quoting from the ancient Chinese military treatise, Sun Tzu’s “The Art of War,” according to a Democratic aide in the room.
“Victorious warriors win first and then go to war, while defeated warriors go to war first and then seek to win,” Mr. Clyburn said. Turning to Ms. Pelosi, he said, “Thank you for winning for us. Now let’s go to war.”
Ms. Pelosi replied by reminding rank-and-file lawmakers to stick together, and to hold fast to the Democrats’ position that they would not negotiate over border security with the president until the government was fully open. “Our unity is our power,” she told them, “and that is what had the president change his mind.”
Republicans portrayed Ms. Pelosi as disrespectful and tried to put a good face on Mr. Trump’s retreat. “I think the president showed some humility, which is an awesome thing,” said Representative Daniel Webster, Republican of Florida.
Even so, some Republicans conceded that Ms. Pelosi had won this round.
“She stood her ground in the initial test,” said former Representative Tom Davis, a Republican who ran the party’s campaign committee. “I think she’s shown she’s an iron woman — and tough as nails.”