The White House and its allies are stepping up their attacks on a foe typically associated with fragile democracies, military coups and spy thrillers.
The "deep state," an alleged shadowy network of powerful entrenched federal and military interests, has increasingly become the focus of Republicans who accuse such forces of trying to undermine the new president.
Though senior White House staff members don't use the exact label, the notion behind it has taken hold. President Donald Trump claims his predecessor tapped his phone and America's intelligence agencies have conspired to leak harmful information to embarrass him. His chief strategist has vowed to dismantle the permanent Washington "administration state." White House spokesman Sean Spicer says "people that burrowed into government" are trying to sabotage the president.
To Trump's critics, these assertions come off as paranoid fear of a non-existent shadow government and an effort to create a scapegoat for the White House's struggles. But to Trump's supporters, this represents an overdue challenge to an elite ruling class concerned only with maintaining its own grasp on power.
"Of course, the deep state exists. There's a permanent state of massive bureaucracies that do whatever they want and set up deliberate leaks to attack the president," said Newt Gingrich, a Trump confidant. "This is what the deep state does: They create a lie, spread a lie, fail to check the lie and then deny that they were behind the lie."
Historians believe the concept of the "deep state" comes from Turkey, where the term "derin devlet" meant a clandestine network, including intelligence and military officers, which protected the ruling class in the 1920s. Similar ideas have taken hold in Egypt, where the military has allied itself with powerful business interests, and Pakistan, with its robust intelligence service.
In its current use, the concept has been twisted and broadened, encompassing a resistant bureaucracy and a regulatory regime rather than foreshadowing some sort of military intervention. Chief Trump strategist Steve Bannon has offered the loudest warnings about the opposition the president is facing from the deep state.
In his only public speech since the election, Bannon told a conservative group that the White House's goal was the "deconstruction of the administrative state," a reflection of his belief that the massive federal government, with its burdensome regulations, does more to hinder than uplift citizens. It also echoes Bannon's oft-stated worldview, frequently on display at his former news site Breitbart, that a global power structure — including government institutions — has rigged the economy.
Gingrich, who says he has discussed the deep state with Bannon, likens its dangers to the plotline of the new season of "Homeland," in which a conspiracy that includes career intelligence officers tries to subvert a president-elect.
"They are fighting to keep hold of their power," said the former House speaker, who asked a reporter not to spoil the two Homeland episodes of the season he has yet to see.
The sprawling federal government, including its intelligence agencies, has thousands of employees who predate Trump, a mix of career staffers and those appointed by President Barack Obama whose replacements have yet to be named.
Trump has insinuated that those holdovers are working against him — even suggesting that leaks from intelligences agencies were reminiscent of smear tactics utilized by Nazi Germany.
Asked if the White House believes there is "a deep state that's actively working to undermine the president," Spicer said recently, "I don't think it should come as any surprise that there are people that burrowed into government during eight years of the last administration and, you know, may have believed in that agenda and want to continue to seek it."
Sean Hannity, a Fox News host who has close to ties to Trump, opened a show last week by claiming there are "deep state Obama holdover government bureaucrats who are hell-bent on destroying this president."
"It's time for the Trump administration to begin to purge these saboteurs before it's too late," Hannity said.
Trump allies note that is customary for presidents to install loyalists and point to Abraham Lincoln's move to push out Southerners from the federal bureaucracy on the eve of the Civil War. The government has also gone through previous spasms of internal suspicion, most notably in the 1950s when Sen. Joseph McCarthy led a witch hunt to root out what he claimed were communist sympathizers supposedly trying to undermine Washington from within.
Experts warn that Trump's attacks could lead to faster erosion of faith in government institutions.
"The more he talks about a deep state cabal against him, the less trust people will have in government," said Matthew Hale, a political science professor at Seton Hall University. "It's deleterious to democracy."
Some of Trump's allies have, without evidence, seized upon Obama's decision to remain in Washington after leaving office as evidence that he is leading the resistance. The former president has said he is staying in the nation's capital until his youngest daughter finishes school.
"He's only there for one purpose and one purpose only and that is to run a shadow government that is totally going to upset the new agenda," said Rep. Mark Kelly, a Pennsylvania Republican, at an event in his home district last week. His office later walked back the remarks.