It has been called a "criminal cabal" rife with corruption. It's been said that its leaders need to be taken out in "handcuffs." And its reputation, one high-placed official has charged, is "in tatters."
The FBI has come under criticism before, but the ongoing barrage of allegations has left its current and former officials shaken. It also has fueled concerns that the bureau's reputation with the public could begin to crumble.
"We're very concerned about the credibility of the FBI because we're having to defend it on a daily basis and we've never had to do that before," said Chris Swecker, who finished his 24-year bureau career as an acting assistant director.
"There's been plenty of controversies but never accusations that the FBI has become a political tool for one party or another, or one set of political beliefs or another."
That is exactly the case, however, that President Trump, Republicans in Congress and their allies have been making for weeks — that "biased" investigators in the FBI and the Justice Department went soft on Hillary Clinton and cooked up a scurrilous case against Trump with the Russia investigation.
The FBI views itself as apolitical and above the petty partisan squabbles of Washington. Taking incoming fire from both Republicans and Democrats, FBI officials like to say, comes with the job.
Past controversies have largely revolved around the FBI's investigative or operational failures—think Ruby Ridge, Waco or Sept. 11. The current criticism, on the other hand, alleges that the FBI has in essence become a political crowbar to kneecap the Trump campaign and White House.
Those advocating this view can often be heard on Fox News.
Host Jeanine Pirro told viewers in December that "there is a cleansing needed in our FBI and Department of Justice," while Tom Fitton, president of the conservative group Judicial Watch said "there was no distinction between the Hillary Clinton campaign and the Department of Justice and the FBI."
Republican House Speaker Newt Gingrich told Fox that "it's pretty appalling, the level of corruption we're beginning to see in the FBI."
The bureau's critics point to anti-Trump text messages sent by a senior FBI agent involved in the Clinton email investigation and the Russia probe. They say those texts support their claims that the FBI is tainted by political bias.
Special counsel Robert Mueller removed the investigator, Peter Strzok, from the Russia unit once his messages came to light as part an internal investigation.
Democrats say the efforts to discredit the FBI are an attempt to distract from Mueller's investigation into possible coordination between the Trump campaign and Russia.
It's difficult to gauge whether the allegations have gained traction with the American public. Anecdotally, at least, former agents say they've had to answer family, friends and even strangers who have one question: what is going on with the FBI?
"We all get asked that. Even FBI agents ask that to each other. What's going on with the bureau? What do you know? Who do you talk to? What have you heard?" said Stephanie Douglas, a retired FBI executive assistant director for the National Security Branch.
Swecker said he was asked over the holidays whether the FBI had become a political tool.
"And what hurts, I think, is that in my conversations with neighbors and friends and family, there are some people who believe it," Swecker said. "If enough people believe it, it will have an impact on the agents on the street trying to conduct their investigation. They rely on people talking to them and believing in the credibility of the FBI."
Douglas, too, worries that the political allegations could hamstring field agents working cases that have nothing to do with politics or Washington, everything from bank robberies and terrorism to white-collar crime or kidnappings.
"There may be some temporary impact. When people feel like an organization like the FBI becomes political, it can impact the trust that certain people give the organization," she said. "Will that impact the public's ability to cooperate with an investigation?"
The political turmoil has bigger consequences for the 7th floor — the executive level — of the FBI's hulking headquarters on Pennsylvania Avenue in Washington than it has for the 56 field offices across the country.
Still, officials worry about the potential impact on work in the trenches.
In office meetings, agents have raised the allegations and the public's perception of the bureau, according to one FBI official who spoke on condition of anonymity in order to discuss internal discussions.
Agents remain focused on their mission — protecting the public — regardless of the political winds, the official said.
Neither FBI Director Christopher Wray nor former leaders have defended Strzok's messages, but they make the case that special agents and analysts and attorneys are allowed to have — and express — opinions.
With 35,000 people at work across the Bureau, such views span the spectrum. But not only would it be wrong to say the FBI is conservative or liberal, defenders argue, the point is that law enforcement officers are sworn to do their jobs without any partisan considerations.
"Obviously, FBI agents have political views," Douglas said. "But when it comes to dealing with investigations, it doesn't really matter what your viewpoint is. The investigations are made by evidence, information, intelligence, and that pulls together the facts that surround an investigation."
Personal opinions do not factor into a successful probe, she said, but "some discretion does need to be employed if you are in the midst of a very political investigation."
The critic in chief
One new wrinkle from periods of turmoil for the FBI is the president using his own bully pulpit to go after the agency.
Trump said in a December tweet that the FBI's reputation "is in Tatters—worst in History!" He's taken aim at the bureau's deputy director, Andrew McCabe, as well as former director James Comey.
Former FBI officials say the criticism from the president and other politicians is short-sighted.
"I think it's important for politicians to remember that the FBI is a core institution of the United States government, and making its mission more difficult or harming its overall credibility is not in the best interests of the country," said Konrad Motyka, a retired special agent and former president of the FBI Agents Association.
The key to that, former officials say, is for FBI workers to keep their heads down and do their jobs.
"It's important that the American people, regardless of their political affiliation, believe in the integrity of the FBI and the objectivity of the FBI," he said.
DAVID GREENE, HOST:
So the FBI is this nation's top law enforcement agency. But it has come under attack from President Trump and his allies. And that has current and former FBI officials worrying about the toll this might take on the bureau's ability to do its job. Here's more from NPR's Ryan Lucas.
RYAN LUCAS, BYLINE: For some two months now, the FBI has found itself the target of a consistent campaign. Headlines in the conservative press and pundits on cable news shows have repeatedly raised questions about its integrity.
(SOUNDBITE OF TV SHOW, "JUSTICE WITH JUDGE JEANINE")
JEANINE PIRRO: There is a cleansing needed in our FBI and Department of Justice.
(SOUNDBITE OF ARCHIVED RECORDING)
NEWT GINGRICH: I think it's pretty appalling, the level of corruption we're beginning to see in the FBI.
(SOUNDBITE OF ARCHIVED RECORDING)
TOM FITTON: There was no distinction between the Hillary Clinton campaign and the Department of Justice and the FBI.
LUCAS: That's Fox News host Jeanine Pirro, former Republican House Speaker Newt Gingrich and the conservative group Judicial Watch's president Tom Fitton. Democrats say the allegations are an attempt to distract from special counsel Robert Mueller's investigation into possible coordination between the Trump campaign and Russia. But for many current and former FBI officials, the immediate political battles are almost secondary to a bigger worry - will the allegations sap Americans' faith in the FBI?
CHRIS SWECKER: We're very concerned about the credibility of the FBI because we're having to defend it on a daily basis. And we've never had to do that before.
LUCAS: That's Chris Swecker. He spent 24 years at the FBI before retiring as an acting assistant director. He says there's been controversy in the past.
SWECKER: But never accusations that the FBI had become a political tool for one party or another.
LUCAS: It's difficult to gauge whether the efforts to discredit the FBI have gained traction with average Americans. Anecdotally at least, former agents say they are having to answer uncomfortable questions from family, friends and neighbors who want to know this - what's going on with the FBI?
STEPHANIE DOUGLAS: We all get asked that. Even FBI agents ask that to each other. What's going on with the bureau? What do you know? Who have you talked to? What have you heard?
LUCAS: That's Stephanie Douglas, a former FBI executive assistant director for the National Security Branch. She and other former officials say they worry the political allegations could hamper the work of agents out on the streets, the ones who are working cases on everything from bank robberies and terrorism to white-collar crimes or kidnappings. Again, Douglas.
DOUGLAS: There may be some temporary impact. When people feel like an organization like the FBI becomes political, it can impact the trust that certain people give to the organization.
LUCAS: It isn't just about politics, though. Douglas worries about agents being able to elicit the help of witnesses.
DOUGLAS: Will that impact the public's ability to cooperate with an investigation?
LUCAS: The potential is a concern. FBI sources tell me that agents have raised the issue of the public's perception of the bureau at office meetings. Critics point to anti-Trump text messages sent by a senior FBI agent involved in the Hillary Clinton email investigation and the Russia probe. They say that supports their claims that the FBI is tainted by political bias. Officials don't defend those texts. But they stress that some 35,000 people work at the FBI. Political opinions span the spectrum. Again, Swecker.
SWECKER: Let's face it, we all have political opinions. Agents vote. That's a political act in and of itself. But if you can't leave that at your house when you go to work as an FBI agent, then you need to be in another line of business. And people recognize that.
LUCAS: There's one aspect of the current criticism that sets it apart from past periods of turmoil. The president himself has repeatedly gone after the FBI. That, former FBI officials say, is shortsighted. Here's Konrad Motyka. He's a retired FBI special agent who also served as the head of the FBI Agents Association.
KONRAD MOTYKA: I think it's important for all politicians to remember that, you know, the FBI's a core institution of the United States government. And making its mission more difficult or harming its overall credibility is not in the best interest of the country.
LUCAS: At the same time, the Russia investigation shows no sign of coming to a close. That may mean the FBI will stay in the political crosshairs, too.
Ryan Lucas, NPR News, Washington.
(SOUNDBITE OF THE POLISH AMBASSADOR'S "DARK BETWEEN STARS") Transcript provided by NPR, Copyright NPR.