WASHINGTON – For the past 17 months since Joseph R. Biden Jr. roused his campaign after an embarrassing fourth place in the Iowa caucuses, Joseph R. Biden Jr. has relied on Anita Dunn, a veteran Washington advisor, for both guidance and guidance as a grudge.

Ms. Dunn, 63, gave direction as Mr. Biden’s campaign took off. She later refused to allow Julian Castro, a former housing minister, a requested speaking time at the Democratic National Convention, still upset by his night of debate against Mr Biden’s mental acuity, according to people familiar with the snub. And so far in the west wing she has helped shape every important political advance.

Now, Ms. Dunn will return to her powerful democratic consultancy, leaving a void in Mr. Biden’s little inner circle as the highly contagious Delta variant permeates unvaccinated communities and the fate of Mr. Biden’s bipartisan infrastructure deal is on the verge of collapse.

“It brings stability and adherence to strategy,” said David Plouffe, the former Obama campaign manager. “You can see it in the White House, where they are very disciplined about Covid, the economy and the President’s commitment. This discipline and not swinging in every pitch is really classic Anita. “

Ms. Dunn has prepared the President for every interview and press conference since taking on his campaign and promoting the government’s buttoned-up approach to the news media. She is widely credited with promoting women to leadership positions in the west wing. And she firmly opposes Mr. Biden asking questions from reporters on a regular basis, which she believes does little to advance his agenda. She prefers town hall events.

But for all of her discipline and expertise, Ms. Dunn’s presence in the Biden administration, and before that in the Obama administration, has raised the question of how her influence in government overlaps with the corporate work of her company, which represents clients who want to influence politics .

Ms. Dunn has just parted ways with SKDK, the business and policy advisory firm she co-founded, and is returning next month for short campaign and government work. And the fact that it is exempt from filing public financial disclosures required by full-time presidential candidates has been criticized by some ethics watchers.

Your presence in the west wing is also evidence of how Mr Biden has prioritized his reliance on trustworthy personalities with decades of experience in the bypass, even as he promised to end access peddling common during the Trump administration. (This week Thomas J. Barrack Jr., a close friend of former President Donald J. Trump and one of his top 2016 fundraisers, was accused of using his access to Mr. Trump to promote the UAE’s foreign policy goals and then reiterated Misleading federal agents about his activities.)

Ms. Dunn and her colleagues have said that she has always scrupulously adhered to ethical rules. The SKDK emphasizes that it does not lobby, but rather provides political and media advice.

Ms. Dunn and her husband Robert Bauer, a former White House attorney who still serves as personal advocate for both Mr. Biden and former President Barack Obama, have long been part of the infrastructure of Washington’s national democratic politics.

Following the 2020 election, Ms. Dunn intended to return to her position as managing director of her company, which represents Pfizer, AT&T and Amazon alongside other corporate giants such as the NAACP

However, Mr. Biden and his wife Jill Biden had other plans. They urged Ms. Dunn to join the new government, reminding her that the pandemic was killing 3,000 people every day and that Mr. Biden relied on her experience and determination.

Ms. Dunn did not feel that she could say no, colleagues said.

She agreed to work for a short term as “special government agent,” a designation that exempts her from the public finance disclosure required of full-time government employees, but also limits the number of days she spends in white A house.

Nor did she intend to oversee Mr Biden’s campaign. But after finishing fourth in the Iowa caucuses, followed by a disastrous fifth place in New Hampshire, Ms. Dunn was motivated by a mixture of loyalty and desperation, according to colleagues.

There was little money in February 2020. There were no crowds. Ms. Dunn took control of the entire operation, lived at a Hampton Inn in Philadelphia near the campaign headquarters, and approved $ 200 in office supplies, colleagues recalled.

Ms. Dunn helped Mr. Biden conclude that the timing was not right. Mr Biden reached out to her again in 2018 when he was seriously considering a run against Mr Trump.

In her current position, she earns a salary of $ 129,000, just below the $ 132,552 threshold that requires filing public financial disclosures. (Mr. Bauer, who is a co-chair of the President’s Commission to Evaluate Proposed Revisions in the Supreme Court, is also a special government official, though his role is unpaid.)

Eleanor Eagan, a research director for the Revolving Door Project, criticized the government for allowing Ms. Dunn to bypass disclosure rules. “Biden has promised to restore confidence in the government after Trump’s fantastically corrupt government,” Ms. Eagan said. “Allowing this and similar evasions is a clear violation of this promise.”

Now Ms. Dunn is returning to the private sector, where her colleagues benefit from her connections in the west wing.

Ms. Dunn’s company was also hired to handle the $ 2.2 million direct mail contract for the Biden campaign, according to the campaign papers, underscoring how the business world and the political world are sometimes aligned.

Some of SKDK’s customers have sparked controversy, such as the case of NSO Group, an Israeli cyber-tech company that The Intercept said was accused of using its spyware to hack the phones of journalists and human rights activists. Hilary Rosen, a partner at SKDK, said she stopped representing the company in 2019 and dropped it as a customer over spyware allegations.

A senior White House official said Ms. Dunn would be subject to the governmental restrictions that apply to former federal employees. This includes a two-year limit on who she contacts on matters in which the government has a “significant interest” that has been pending under its official responsibility in the White House.

Even with her return to the company, no one at the White House expects Ms. Dunn’s influence in the Biden world to end completely. Indeed, many view her departure as a moment to take a deep breath before she begins planning the president’s re-election, which he has so far announced.

“She will always be a phone call away,” said Cedric Richmond, a senior adviser to the White House.