WASHINGTON — Intelligence officials warned House lawmakers last week that Russia was interfering in the 2020 campaign to try to get President Trump re-elected, five people familiar with the matter said, a disclosure to Congress that angered Mr. Trump, who complained that Democrats would use it against him.
The day after the Feb. 13 briefing to lawmakers, Mr. Trump berated Joseph Maguire, the outgoing acting director of national intelligence, for allowing it to take place, people familiar with the exchange said. Mr. Trump cited the presence in the briefing of Representative Adam B. Schiff, the California Democrat who led the impeachment proceedings against him, as a particular irritant.
During the briefing to the House Intelligence Committee, Mr. Trump’s allies challenged the conclusions, arguing that he has been tough on Russia and strengthened European security. Some intelligence officials viewed the briefing as a tactical error, saying that had the official who delivered the conclusion spoken less pointedly or left it out, they would have avoided angering the Republicans.
That intelligence official, Shelby Pierson, is an aide to Mr. Maguire who has a reputation of delivering intelligence in somewhat blunt terms. The president announced on Wednesday that he was replacing Mr. Maguire with Richard Grenell, the ambassador to Germany and long an aggressively vocal Trump supporter.
Though some current and former officials speculated that the briefing may have played a role in the removal of Mr. Maguire, who had told people in recent days that he believed he would remain in the job, two administration officials said the timing was coincidental. Mr. Grenell had been in discussions with the administration about taking on new roles, they said, and Mr. Trump had never felt a kinship with Mr. Maguire.
Spokeswomen for the Office of the Director of National Intelligence and its election security office declined to comment. A White House spokesman did not immediately respond to requests for comment.
A Democratic House intelligence committee official called the Feb. 13 briefing an important update about “the integrity of our upcoming elections” and said that members of both parties attended, including Representative Devin Nunes of California, the top Republican on the committee.
Mr. Trump has long accused the intelligence community’s assessment of Russia’s 2016 interference as the work of a “deep-state” conspiracy intent on undermining the validity of his election. Intelligence officials feel burned by their experience after the last election, where their work became subject of intense political debate and is now a focus of a Justice Department investigation.
Part of the president’s anger over the intelligence briefing stemmed from the administration’s reluctance to provide sensitive information to Mr. Schiff. He has been a leading critic of Mr. Trump since 2016, doggedly investigating Russian election interference and later leading the impeachment inquiry into the president’s dealings with Ukraine.
After asking about the briefing that the Office of the Director of National Intelligence and other agencies gave to the House, Mr. Trump complained that Mr. Schiff would “weaponize” the intelligence about Russia’s support for him, according to a person familiar with the briefing. And he was angry that no one had told him sooner about the briefing, the person said.
Mr. Trump has fixated on Mr. Schiff since the impeachment saga began, pummeling him publicly with insults and unfounded accusations of corruption. At one point in October, Mr. Trump refused to invite lawmakers from the congressional intelligence committees to a White House briefing on Syria because he did not want Mr. Schiff there, according to three people briefed on the matter.
Mr. Trump did not erupt at Mr. Maguire, and instead just asked pointed questions, according to the person. But the message was unmistakable: He was displeased by what took place.
Ms. Pierson, officials said, was delivering the conclusion of multiple intelligence agencies, not her own opinion. The Washington Post first reported the Oval Office confrontation between Mr. Trump and Mr. Maguire.
The intelligence community issued an assessment in early 2017 that President Vladimir V. Putin personally ordered an influence campaign in the previous year’s election and developed “a clear preference for President-elect Trump.” But Republicans have long argued that Moscow’s campaign was designed to sow chaos, not aid Mr. Trump specifically.
And some Republicans have accused the intelligence agencies of opposing Mr. Trump, but intelligence officials reject those allegations. They fiercely guard their work as nonpartisan, saying it is the only way to ensure its validity.
At the House briefing, Representative Chris Stewart, a Utah Republican who has been considered for the director’s post, was among the Republicans who challenged the conclusion about Russia’s support for the president. Mr. Stewart insisted that Mr. Trump has aggressively confronted Moscow, providing anti-tank weapons to Ukraine for its war against Russian-backed separatists and strengthening the NATO alliance with new resources, according to two people briefed on the meeting.
Mr. Stewart declined to discuss the briefing but said that Moscow had no reason to support Mr. Trump. He pointed to the president’s work to confront Iran, a Russian ally, and encourage European energy independence from Moscow. “I’d challenge anyone to give me a real-world argument where Putin would rather have President Trump and not Bernie Sanders,” the nominal Democratic primary front-runner, Mr. Stewart said in an interview.
Under Mr. Putin, Russian intelligence has long sought broadly to sow chaos among adversaries around the world. The United States and key allies on Thursday accused Russian military intelligence, the group responsible for much of the 2016 election interference in the United States, of a cyberattack on neighboring Georgia that took out websites and television broadcasts.
Though intelligence officials have previously informed lawmakers that Russia’s interference campaign was ongoing, last week’s briefing did contain what appeared to be new information, including that Russia intends to interfere with the ongoing Democratic primaries as well as the general election.
The Russians have been preparing — and experimenting — for the 2020 election, undeterred by American efforts to thwart them but aware that they needed a new playbook of as-yet-undetectable methods.
They have made more creative use of Facebook and other social media. Rather than impersonating Americans as they did in 2016, Russian operatives are working to get Americans to repeat disinformation to get around social media companies’ rules that prohibit “inauthentic speech.”
And they are working from servers located in the United States, rather than abroad, knowing that American intelligence agencies are prohibited from operating inside the country. (The F.B.I. and the Department of Homeland Security can, with aid from the intelligence agencies.)
Russian hackers have also infiltrated Iran’s cyberwarfare unit, perhaps with the intent of launching attacks that would look like they were coming from Tehran, the National Security Agency has warned.
Some officials believe that foreign powers, possibly including Russia, could use ransomware attacks, like those that have debilitated some local governments, to damage or interfere with voting systems or registration databases.
Still, much of the Russian aim is similar to its 2016 interference, officials said: Search for issues that stir controversy in the United States and use various methods to stoke division.
One of Moscow’s main goals is undermining confidence in American election systems, intelligence officials have told lawmakers, seeking to sow doubts over close elections and recounts. Confronting those Russian efforts is difficult, officials have said, because they want to maintain American confidence in voting systems.
Both Republicans and Democrats asked the intelligence agencies to hand over the underlying material that prompted their conclusion that Russia again is favoring Mr. Trump’s election.
How soon the House committee might get that information is not clear. Since the impeachment inquiry, tensions have risen between the Office of the Director of National Intelligence and the committee. As officials navigate the disputes, the intelligence agencies have slowed the amount of material they provide to the House, officials said. The agencies are required by law to regularly brief Congress on threats.
While Republicans have long been critical of the Obama administration for not doing enough to track and deter Russian interference in 2016, current and former intelligence officials said the party is at risk of making a similar mistake now. Mr. Trump has been reluctant to even hear about election interference, and Republicans dislike discussing it publicly.
The aftermath of last week’s briefing prompted some intelligence officials to voice concerns that the White House will dismantle a key election security effort by Dan Coats, the former director of national intelligence: the establishment of an election interference czar. Ms. Pierson has held the post since last summer.
And some current and former intelligence officials expressed fears that Mr. Grenell may have been put in place explicitly to slow the pace of information on election interference to Congress. The revelations about Mr. Trump’s confrontation with Mr. Maguire raised new concerns about Mr. Grenell’s appointment, said the Democratic House committee official, who added that the upcoming election could be more vulnerable to foreign interference.
Mr. Trump, former officials have said, is typically uninterested in election interference briefings, and Mr. Grenell might see it as unwise to emphasize such intelligence with the president.
“The biggest concern I would have is if the intelligence community was not forthcoming and not providing the analysis in the run-up to the next election,” said Andrea Kendall-Taylor, a former intelligence official now with the Center for New American Security. “It is really concerning that this is happening in the run-up to an election.”
Mr. Grenell’s unbridled loyalty is clearly important to Mr. Trump but may not be ideally suited for an intelligence chief making difficult decisions about what to brief to the president and Congress, Ms. Kendall-Taylor said.
“Trump is trying to whitewash or rewrite the narrative about Russia’s involvement in the election,” she said. “Grenell’s appointment suggests he is really serious about that.”
The acting deputy to Mr. Maguire, Andrew P. Hallman, will step down on Friday, officials said, paving the way for Mr. Grenell to put in place his own management team. Mr. Hallman was the intelligence office’s principal executive, but since the resignation in August of the previous deputy, Sue Gordon, he has been performing the duties of that post.
Mr. Maguire is planning to leave government, according to an American official.
Eric Schmitt and David E. Sanger contributed reporting.