White House Budget Director Mick Mulvaney speaks outside the West Wing on Monday, after Congress's nonpartisan budget analysts reported that 14 million people would lose coverage next year under the House bill dismantling President Barack Obama's health-care law. (Andrew Harnik/AP)

The Congressional Budget Office’s explosive report Monday that projected a Republican health-care bill would lower the number of Americans with health insurance by 24 million over a decade triggered a blistering backlash from the Trump administration, with senior White House officials working to undermine the independent budget office’s credibility.

CBO officials are often political punching bags, but vitriolic attacks from top White House officials in recent days have the potential to erode the agency’s standing at a time when its assessments of health-care policy, changes to the tax code and deficit projections will factor into whether Congress enacts key parts of the Trump administration’s agenda.

“It’s always been my concern that these attacks undermine this institution that’s been there for 40 years and served Republicans and Democrats and independents all this time,” said William Hoagland, a former Republican staff director on the Senate Budget Committee.

Trump and his top advisers have routinely worked to discredit government entities that publish forecasts, estimates or reports. Trump has suggested, for example, that the Bureau of Labor Statistics’ data on unemployment cannot be trusted.

On Monday, White House Office of Management and Budget Director Mick Mulvaney told reporters that part of the CBO report was “absurd,” and Health and Human Services Secretary Tom Price said, “We disagree strenuously with the report that was put out.” White House press secretary Sean Spicer said last week that “If you’re looking at the CBO for accuracy, you’re looking in the wrong place.”

(Sarah Parnass,Bastien Inzaurralde/The Washington Post)

Anticipating that the CBO head would get major blowback after releasing his assessment, Hoagland said he sent an email Monday morning to Director Keith Hall, telling him “he was doing the job he was supposed to do and not take anything personal in terms of criticism.”

Hall, a conservative economist, responded to the email, Hoagland said, writing that “he was doing the job he’s paid to do.”

The CBO declined to comment for this report.

The entity’s analysis will be crucial for some of the Trump administration’s more-controversial proposals this year, and it could repeatedly issue assessments that run counter to what the White House thinks. Its analysis, for example, of the White House’s proposed tax cut plan could find that large reductions in corporate or individual tax rates could lead to a big spike in the deficit. It could also issue a report about the economic impact of building a wall along the U.S.-Mexico border.

Democrats routinely quarreled with the CBO during the drafting of the Affordable Care Act in 2009, but they rushed to Hall’s defense Monday.

“They appointed this person,” Senate Minority Leader Charles E. Schumer (D-N.Y.) said. “He was supposed to be a conservative person. Unfortunately for Republicans, he’s also an honest person.”

Not all congressional Republicans dismissed the CBO report as quickly as the White House.

(Daron Taylor/The Washington Post)

“I’m concerned about it, but let’s face it, this is a tough baby to take care of and there will be some people who are left out,” said Senate Finance Committee Chairman Orrin G. Hatch (R-Utah). “There isn’t enough money in the world to cover everybody the way they’d like to be covered.”

The CBO was created in 1975 and is supposed to offer independent assessments of legislative proposals, as well as to offer policy and economic projections for lawmakers. The director is appointed by Congress, but its staff is mostly budget and policy experts who steer clear of political prognostication. On its website, CBO describes itself as “strictly nonpartisan.”

Hall was hand-picked for the CBO job in 2015 by congressional Republicans, including Price, who at the time was a GOP congressman from Georgia. His term expires in 2019. Hall served as commissioner of the BLS from 2008 until 2012.

Before that, he had served as chief economist at the White House’s Council of Economic Advisers, among other things. Although he has not attracted as much attention in his tenure as some of his predecessors, that is likely to change now that he will be judging the costs and impact of many bills that the White House and congressional Republicans want to advance.

Before Trump ran for president, he routinely cited the CBO as an authority when criticizing Democrats on tax policy, economic growth or the 2009 stimulus law.

In 2014, he tweeted, “Congrats to Pres. Obama and Dems. CBO has TRIPLED its estimate of working hours lost due to ObamaCare.” He added that it was a “Job Killer.”

As much as lawmakers from both parties like to complain about the CBO, similar to the way sports coaches bark at a referee, they also are exalted when the agency projects that their bill does what they say it will do. And although CBO officials attempt to use the most sophisticated modeling, they often say that their projections are just that — projections — and not perfect estimates of what any bill ultimately will look like.

That hasn’t stopped the ­complaining.

Robert Reischauer, a Democrat who was CBO director during the George H.W. Bush and Clinton administrations, was routinely jabbed for his projections by the Clinton administration, but he said in an interview that he learned how to weather the ­criticism.

“To be CBO director and sleep at night, you have to have the hide of a rhinoceros,” he said. “You are subject to criticism all the time.”

The Obama administration routinely objected to CBO assessments, but it often challenged CBO’s methodology or forecast modeling and didn’t dismiss reports outright.

For example, in 2014, the CBO, led at the time by Democrat Douglas Elmendorf, found that raising the minimum wage to $10.10 per hour would eliminate about 500,000 jobs but increase pay for millions of Americans. Republicans pounced on the report, saying that raising the minimum wage would be a job killer. The Obama administration protested, but the CBO report helped rally opposition to a federal increase of the minimum wage, and one never occurred.

Jason Furman, who was chairman of the White House Council of Economic Advisers during the Obama administration, said he would always carefully choose his words when debating CBO decisions in public, trying to stick to specific policy debates and not working to attack the entity’s credibility or legitimacy.

“This administration likes to argue with facts,” Furman said in an interview. “And if they don’t like what’s produced by BLS or CBO, they attack the messenger. At a time when there’s increasing distrust in institutions, that’s like playing with fire.”

Mike DeBonis and Kelsey Snell contributed to this report.