It’s not often that you hear members of the FBI threatening to go to war with the president. But that’s where we are after Donald Trump’s firing of FBI Director James Comey.

“[Trump] essentially declared war on a lot of people at the FBI,” an anonymous FBI official told the Washington Post. “I think there will be a concerted effort to respond over time in kind.”

There’s every reason to believe that the FBI is as angry as this official says. Interim FBI Director Andrew McCabe told Congress last week that “the vast majority of employees enjoyed a deep, positive connection to Director Comey.” Reports from inside the bureau suggest horror and rage after the firing; one agent told the Daily Beast that “everyone feels like there has been a death in the family.”

And indeed, it’s possible we’re starting to see the first shots in this “war.” On Tuesday, the New York Times revealed a memo written by Comey detailing a conversation with Trump wherein the president asked him to drop the investigation into former National Security Adviser Michael Flynn. It’s a highly embarrassing leak for the president, one that suggests that he obstructed an ongoing investigation. It was provided by an“associate” (in the Times’ words) of the former director’s.

If this “associate” turns out to be bureau agent, it would make a lot of sense. The FBI values its independence from the political branches above all else, an independence directly threatened by Trump firing Comey in retaliation for the Russia investigation. Historically, the bureau has been willing to fight — and fight dirty — to stay independent.

“The FBI is a tribal organization,” Ben Wittes, a senior fellow in governance studies at the Brookings Institution, tells me. “You screw with the FBI, you screw with the institution of the FBI, and ... a lot of people are gonna be angry.”

So let’s say that the official’s comments to the Washington Post are right: that we’re about to see elements of the FBI launch a full-scale offensive against Trump in retaliation for the Comey firing.

I asked both Wittes, who’s very familiar with the current FBI’s practices, and Douglas Charles, a historian of the FBI at Penn State, what the FBI could actually do — in practical terms — to undermine and weaken the Trump presidency.

Their answer? Quite a lot.

The bureau could leak damaging information to the press like the Comey memo. It could work more closely with Congress to strengthen the legislative probes into Russia. It could intensify its own Russia investigation, or even open new investigations into Trump and his allies.

Any one of these actions, theoretically, could do serious damage to Trump’s already chaotic and politically vulnerable administration. And, according to Charles, one of them is “probably” inevitable.

This is one fight the president may soon regret picking.

Leaks, leaks, leaks

The first and most obvious thing the FBI could do is talk to the press.

“The FBI has a really long history of leaking to various outlets who could advance their own bureaucratic interests,” Charles says. “There could be some very good amount of leaking happening soon, if there’s not already.”

The most famous leaker in US history — the pseudonymous Deep Throat, who gave sensitive information on the Nixon administration to Washington Post journalists Bob Woodward and Carl Bernstein in 1972-3 during the Watergate scandal — was later revealed to be Mark Felt, who was associate FBI director at the time.

Interestingly, Felt’s motivation for leaking about Watergate wasn’t whistleblowing: He wasn’t motivated by some patriotic sense of duty to protect American democracy. Rather, he believed he was acting to protect the FBI’s independence from Nixon’s attempts to rein it in.

“He was doing that because Nixon appointed a sycophant, L. Patrick Gray, as FBI director,” Charles explains. “He wasn’t leaking out of some sympathy for Woodward and Bernstein or Watergate, but for his own interests — to undermine Gray.”

It “wouldn’t surprise me whatsoever,” Charles continued, if this were to happen again in this case. A senior FBI official decides that Trump is a threat to the FBI, and begins leaking damaging information that the FBI has on the president to reporters.

That could start, obviously, with any troubling facts the FBI may have uncovered so far in the Russia investigation.

In late March, CNN reported that “the FBI has information that indicates associates of President Donald Trump communicated with suspected Russian operatives to possibly coordinate the release of information damaging to Hillary Clinton's campaign.”

CNN didn’t say what that information was, exactly — was it a phone call between a Trump ally and Russian intelligence? Compromising emails? — but it’s pretty likely that its release would be embarrassing for the Trump administration. And presumably there’s more where that came from, given that the FBI’s investigation into Trump and Russia has only grown in the past month and a half.

“They could do that without ever getting caught”

These leaks wouldn’t necessarily have to be authorized at the highest levels. A few disgruntled agents with access to the right information could contact the press on their own. Indeed, that’s what appeared to happen last summer, when information about the investigation into Hillary Clinton’s emails kept drip-drip-dripping out of the bureau’s New York field office.

“I have not seen a lot of evidence of leaks out of this Russia investigation. In fact, I haven’t really seen any,” Wittes says. But “I don’t deny the possibility that you could imagine individual agents doing that stuff [now].”

Assuming the FBI investigation is as serious as it seems — and given that acting FBI Director McCabe testified Thursday that the investigation was “highly significant,” it probably is — the information it has is likely far more specific and damning than what we’ve seen so far.

Fighting them would consume huge amounts of Trump’s time and energy — and could potentially grind his legislative agenda to a halt, as Congress holds hearing after hearing on whatever the FBI tells the press.

It’d be especially painful since FBI investigations usually take a long time to conclude, which means the information could continue to drip out for quite a while. The sooner it started to come to light, the sooner it would start messing up Trump’s political agenda.

Working with Congress

The FBI is technically part of the Justice Department — and thus the executive branch. But in reality, it operates sort of like a freestanding bureaucracy, with conduits to other parts of the government that don’t involve going through the White House or the attorney general.

The most important of these bureau relationships, for present purposes, is with Congress. Both the House and Senate Intelligence Committees are currently conducting investigations into Trump’s ties with Russia. The House investigation is a bit of a mess — remember Devin Nunes? — but the Senate’s is pretty serious. Its biggest problem is that the Senate has given it limited funding and limited access to trained investigators.

The FBI can help with that.

“There’s a thousand ways in which, for example, the Senate Intelligence Committee investigation depends on cooperation institutionally from the intelligence community,” Wittes says. “That cooperation can be more or less robust. An FBI that really believes its independence is under attack is going to have a deeper relationship with its overseers, whose job, among other things, is to protect its independence.”

Wittes thinks this is one of the most likely ways that post-Comey resistance will manifest. The FBI will devote more resources to helping along the congressional investigations, which will help those investigations become more credible and more effective. The more Trump is being pressured on Russia by Congress, the harder it will be for him to try to install a crony atop the FBI and get Senate consent for it.

Even if this doesn’t happen, the FBI has ways of working with Congress outside of official channels. This is a different sort of leaking, where information uncovered by the bureau just so happens to end up in the hands of a friendly member of Congress, who then either leaks this information to the press herself or threatens the president with it behind closed doors.

This used to happen a lot more frequently in the days of the legendarily vicious FBI Director J. Edgar Hoover. Hoover had dossiers on everyone, and contacts in all different parts of the government for disseminating them.

In 1953, in the midst of a moral panic about gays in government known as the Lavender Scare, Hoover had set up specific contacts in each branch of government for leaking information that someone was a “Sex Deviate” — an operation explicitly authorized via an executive order signed by President Dwight Eisenhower.

When Hoover wanted to get rid of someone or block their nomination, he would discreetly hand off that person’s file to the relevant contact at the White House or the Capitol. That tactic torpedoed a number of careers, including that of Arthur Vandenberg Jr., whom Eisenhower had picked to be his top aide.

After Hoover died in 1972, Congress put in place a number of reforms aimed at limiting the FBI’s influence — and since then, that kind of super-shady stuff has presumably happened a lot less frequently. But the FBI still knows how to discreetly hand off information to Congress if need be.

Charles floated a hypothetical in which Trump appointed someone the FBI didn’t like to be its new director. You could easily imagine, in that scenario, the bureau handing off damaging information it has about that person to a cooperative senator — and that senator using the information to prevent Trump’s nominee from ever being confirmed.

“They could do that without ever getting caught, and it would perfectly fit their history as well,” he says.

Ramping up investigations into Trump — even beyond Russia

Q: Did Comey's firing impede any investigation?



McCabe: “you cannot stop the men and the women of the FBI from doing the right thing” pic.twitter.com/4hSqb2IXlM — Bradd Jaffy (@BraddJaffy) May 11, 2017

Of course, the most obvious way to defy Trump is to do the opposite of what he wants: to ramp up the Russia investigation, devoting more staff and resources to it rather than fewer. Acting FBI Director McCabe already signaled that he would do just that in his testimony to the Senate (embedded above), telling Sen. Marco Rubio that “you cannot stop the men and the women of the FBI from doing the right thing.”

But the ways in which the FBI could mess with Trump directly go well beyond Russia.

Trump has done a lot of things that might invite law enforcement scrutiny, but weirdly haven’t. My colleague Matt Yglesias lists them:

And that’s to say nothing of Trump’s sketchiest associates, like Michael Flynn, Carter Page, and Roger Stone.

Now, the FBI can’t just decide to investigate any one of these Trump-related issues because it wants to. It needs a piece of information that gives it cause to believe criminal activity or some kind of national security threat is present. In FBI language, this is called “predication.”

There are certain standards for what information can “predicate” an investigation. But the FBI, Wittes says, has “a fair bit of discretion” among “individual agents [and] field offices” as to when to start looking at something. He said he could easily imagine that some agents, furious about Comey’s firing, might start looking into other allegations about Trump that the FBI may have received tips about — be they on Russia or something else.

“If you think about how sprawling the allegations are about this group of people, and you imagine that the bureau is more rather than less angry,” Wittes says, “that might very well shade the way you understand allegations that may drift in your door: how seriously you take them, how you weigh them against traditional predication standards.”

Wittes suggests an analogy to the way the FBI investigates organized crime, the arrest of Al Capone on tax evasion charges being the most famous example. When someone is a target of suspicion on one set of charges that the FBI can’t necessarily make, the bureau is more likely to go after them on whatever case it can conceivably put together.

“If you believe someone’s dirty, and you get what would otherwise be a tip that you might not investigate against another person — well, it’s a mobster,” he says.

The point, in short, is that Trump is vulnerable and the FBI is extremely powerful. Starting a fight with the bureau is inadvisable for every president, and especially so for a president with a history of legal problems. But by firing Comey, Trump has invited war.