After El Paso shooting, Trump pushed again on gun control. His aides talked him out of it.

One of the most extraordinary moments of Donald J. Trump’s presidency was an hourlong meeting with U.S. senators in the aftermath of the school shooting in Parkland, Fla., in which he forcefully argued for a litany of gun safety measures that the National Rifle Association had long opposed.

Mr. Trump’s support for gun control measures — which he unrolled on live television from the White House on Feb. 28, 2018 — astonished lawmakers from both parties. But the next day, N.R.A. officials met with Mr. Trump without any cameras or reporters in the room, and he immediately backed down.

That apparent surrender to N.R.A. pressure came to sum up Mr. Trump’s record on gun control in the eyes of his critics.

Unbeknownst to the public, however, Mr. Trump again pushed inside the White House for significant new gun-control measures more than a year later, after a pair of gruesome shooting sprees that unfolded over 13 hours. Those discussions have not previously been reported.

On Aug. 3, 2019, a far-right gunman killed 23 people at a Walmart store in El Paso. Early the next morning, a man shot and killed nine people outside a bar in Dayton, Ohio. Both assailants used semiautomatic rifles.

At the White House the next day, Mr. Trump was so shaken by the weekend’s violence that he questioned aides about a specific potential solution and made clear he wanted to take action, according to three people present during the conversation.

“What are we going to do about assault rifles?” Mr. Trump asked.

“Not a damn thing,” Mick Mulvaney, his acting chief of staff, replied.

“Why?” Trump demanded.

“Because,” Mr. Mulvaney told him, “you would lose.”

Mr. Trump never pursued an assault weapons ban, though he had called for one in his 2000 book, “The America We Deserve” — in which he also criticized Republicans for opposing even limited gun restrictions.

Mr. Trump was scheduled to face the N.R.A. again on Friday in Houston, where he’ll address the gun group’s annual conference. The event is taking place days after a gunman killed 19 children and two adults at an elementary school in Uvalde, Texas.

“America needs real solutions and real leadership in this moment, not politicians and partisanship,” Mr. Trump said in a social media post this week after the school massacre, explaining his decision to speak at the event.

Other scheduled speakers, including Gov. Greg Abbott of Texas, have opted to skip the meeting.

Mr. Trump’s repeated interest in pushing for gun control as president flew in the face of his public image as an absolutist on Second Amendment issues who fiercely guarded his standing with the N.R.A.

On the campaign trail in 2016, he promised to abolish gun-free schools on his first day in office and claimed that he sometimes carried a concealed weapon. “I feel much better being armed,” he said on CBS’s “Face the Nation” during the Republican primary.

Seeking re-election in 2020, Mr. Trump told voters that he had “saved the Second Amendment.”

But the reality was more complicated.

After both the Florida school shooting at Marjory Stoneman Douglas High School in 2018 and again in the summer of 2019, Mr. Trump publicly pushed for more background checks before gun purchases and talked about raising the age requirement to buy guns to 21 from 18.

The gunman who carried out the Uvalde massacre was 18, as was the man accused of killing 10 Black people at a supermarket in Buffalo on May 14.

“We have tremendous support for really common-sense, sensible, important background checks,” Mr. Trump told reporters in August 2019.

Mr. Trump entered office in 2017 largely unencumbered by his party’s orthodoxy, or by any particular political ideology, relying mostly on his own instincts. He carried no scars from the battlefield of intellectual conservatism, where debates over the merit of supply-side tax cuts, health-care policy and gun rights had shaped a generation of Republicans.

He’d been a registered Democrat and a Republican and donated hundreds of thousands of dollars to candidates in both parties. For issues beyond trade and immigration, Mr. Trump’s initial reaction was often to side with public opinion polls and support ideas that no other recent Republican president would have considered.

That often occurred on gun issues. And it often fell to Mr. Trump’s aides in the administration, including Vice President Mike Pence, to pull him back into positions where Republicans were most comfortable.

According to people familiar with the conversations, Mr. Pence was particularly influential in speaking with Mr. Trump after the shootings in 2018 and 2019.

“He has those Democrat talking points in his head,” one White House policy adviser said of Mr. Trump, “because he lived in New York forever.”

On Second Amendment issues, Mr. Trump’s team often wore him down by burying him in the technical details of gun policy.

Indeed, in the August 2019 conversation, when Mr. Trump suggested he wanted to find a way to ban assault weapons, Mr. Mulvaney asked how he defined them, according to the people in the room. Commonly, the term refers to a class of weapons including the AR-15 semiautomatic rifles regularly used in mass shootings.

“Well, it’s the military weapons,” Mr. Trump responded.

Legally, AR-15s are civilian versions of a military weapon that has been heavily regulated since the 1930s.

“Mr. President,” Mr. Mulvaney shot back, “military assault weapons are already against the law.”

The president abandoned the idea.