Shaun Donovan, who served as OMB director under President Barack Obama and speaks regularly with career officials at the agency, said “the damage is deep and wide” at the agency.

“I’ve seen these moments over and over again, and there is no comparison,” Donovan said of past presidential transitions. “This is easily the most perilous and has the deepest damage to be repaired.”

In the new president's first three days in office, the Biden administration has given career staff back their power in overseeing federal spending and released more than $27 billion for critical services temporarily frozen by Trump’s recent request for spending cuts, said Rob Friedlander, associate director for communications at OMB.

The Trump administration had shifted that power to political appointees, away from high-ranking career officials who traditionally held it, POLITICO first reported last year.

"We are fully committed to drawing on the talents and expertise of the entire OMB team," Friedlander said, "particularly the incredibly dedicated and experienced career staff — to deliver on the President’s agenda and ensure our government works for all Americans."

During the Trump administration, the share of OMB employees who said they disagree that the agency's "senior leaders maintain high standards of honesty and integrity" grew to about a third of the agency’s employees by 2019.

A former senior OMB official who served under both Democratic and Republican presidents said that "instead of OMB being a resource for the White House," the Trump administration "turned OMB into a tool of the White House."

"And that’s a very different thing,” the former official said. “That’s a dangerous thing.”

OMB will have its hands in every part of Biden’s agenda — pulling together his first budget proposal, reviewing and approving all federal regulations before they can take effect and overseeing financial management issues, federal procurement and information technology.

But the agency's workforce doesn't seem to have "a lot of gas left in the tank right now," the former official said. “You’ve got a staff that is tired. They’ve been running for four years and running in directions that they don’t actually believe in. I don’t know that they’ll have the energy needed to respond in the way that the Biden administration would traditionally expect an OMB to respond.”

The Biden administration is staffing up, announcing a slate of key political hires over the weekend.

Topher Spiro, who led health policy work at the Center for American Progress, has joined the agency as associate director for health. Danny Yagan, an economics professor at the University of California, Berkeley, will be associate director for economic policy, after advising Pete Buttigieg during his presidential run. University of Michigan law professor Sam Bagenstos has joined as general counsel.

The Biden administration has also brought on two former Senate Budget Committee aides at OMB. Michael Linden, who was a senior policy adviser to Sen. Patty Murray (D-Wash.) on the panel, has joined the agency as a senior adviser. Bobby Kogan, former chief mathematician for the committee, will serve as an adviser.

Under Trump, one major criticism of the budget office is that it functioned as a rubber stamp for the Oval Office, demolishing precedents in service of the president’s agenda. While OMB under past administrations has drawn up creative interpretations to push through initiatives and regulations that might run into challenges or legal trouble, former officials argue that it is typically in service of the greater good.

When Trump called in 2019 for the budget office to pause aid to Ukraine after suggesting the Eastern European country investigate Biden, career staff balked at the political appointees who went ahead with it anyway, and the move motivated the resignation of at least two civil servants. The Government Accountability Office later said the aid freeze — which fueled Trump’s first impeachment — ran afoul of federal budget law.

Outgoing OMB Director Russ Vought said this week that Democrats’ requests for the budget office to reverse course on several major policies “amount to ongoing congressional overreach and micromanagement of the executive branch’s authority to manage taxpayer dollars wisely.”

“The Biden Administration will have to decide if they’re going to run the executive branch or be run by the legislature,” he said in a statement.

Under Biden, the budget office could soon be run by a longtime aide for the legislative branch. The new president has nominated Shalanda Young, outgoing staff director and clerk for the House Appropriations Committee, to be deputy secretary at OMB under Neera Tanden, who has a broad base of policy expertise as a political operative and the president of the liberal Center for American Progress.

OMB’s stalling of congressional inquiries is expected to come to an abrupt end once Young and Tanden are confirmed, Rep. John Yarmuth (D-Ky.), the chair of the House Budget Committee, said in an interview.

“Neera understands the role of OMB and how critical it is, and she’s going to want to do things with a unified Democratic government,” Yarmuth said. “There shouldn’t be any conflict. There shouldn’t be any tension. And I’m looking forward to that.”