This piece was drawn from “In Deep: The F.B.I., the C.I.A., and the Truth about America’s ‘Deep State,’ ” by David Rohde, published by Norton.

On July 2, 1881, President James A. Garfield arrived at Washington, D.C.,’s Baltimore and Potomac Railroad Station to depart for summer vacation. An Ohio Republican, Garfield was considered one of his era’s most promising Presidents; at forty-nine years old, he was the third-youngest man ever elected to the office. As he walked arm-in-arm across the station with his friend, Secretary of State James G. Blaine, a forty-year-old lawyer turned bill collector turned preacher named Charles Guiteau walked up behind him and pulled out a revolver. Guiteau fired two shots into the President’s back. One missed, grazing Garfield’s arm; the other struck dead center. Before being taken away by the police, Guiteau bizarrely declared his loyalty to Chester A. Arthur, Garfield’s Vice-President: “I am a Stalwart, and Arthur is President now,” he shouted. News of the shooting spread instantly, via telegraph, across the country. For the next seventy-nine days, Garfield lingered, his health improving and declining, in part due to botched medical care. On September 19th, he died.

The public raged at Guiteau, a delusional political wannabe who believed he deserved an appointment as a U.S. official in Europe. While Guiteau considered himself an important Garfield supporter, he was actually just one of thousands of hangers-on who hoped to obtain a post in the federal government under what was then known as the “spoils system,” in which each new President appointed thousands of supporters to federal jobs, prioritizing loyalty over merit. (“To the victor belong the spoils,” as one senator put it.) Under such a system corruption was rampant, but a country still divided after the Civil War lacked the political will to address it. Garfield’s death proved a turning point. Sixteen months later, on January 16, 1883, Congress passed and Arthur signed the Pendleton Act, a historic government reform mandating that almost all federal employees had to be hired on the basis of skills, training, and education, rather than political patronage. The act would give Americans the benefit of an independent, professional civil service—one which was answerable to elected officials without being beholden to them.

Last week, President Trump signed Executive Order 13957. Although its title, “On Creating Schedule F in the Excepted Service,” is almost aggressively banal, it is an unprecedented election-eve power grab that could undo much of the Pendleton Act. The order could strip hundreds of thousands of federal officials of their civil-service protections, allowing them to be quickly dismissed, like political appointees. It has the potential to expand the number of people appointed by each President from about four thousand to hundreds of thousands. “It’s an attempt to redefine the civil service as a political arm of the Presidency rather than public servants who work for the American people,” Don Beyer, a Democratic representative from Virginia, told the Washington Post. Democrats have decried the order as a return to Civil-War-era cronyism. Some conservatives, however, have praised it as a brave attempt to tame the “deep state.”

The imaginary “deep state”—a permanent, unelected shadow government which is said to have relentlessly gathered power to itself—has long served as a foil for Trump. According to the President and his allies, the deep state might include not just power-mad F.B.I. and C.I.A. agents but military leaders, journalists, tech executives, and F.D.A. regulators; some have extended it to include infectious-disease experts fighting the pandemic, such as Anthony Fauci. The idea of the deep state saturates Trump’s rhetoric and worldview. His Presidency is predicated on the idea that the United States government is itself an enemy of the people. “Somebody said, President, what’s the toughest country to deal with? Is it Russia? Is it China? Is it North Korea?” Trump told attendees, at a recent fund-raiser. “No, the toughest country by far is dealing with the United States. It’s true. These people are sick.” On the day that he signed the civil-service executive order, the President tweeted, “I am not just running against Biden, I am running against the Corrupt Media, the Big Tech Giants, and the Washington Swamp.”

Since entering politics, Trump has trafficked in conspiracy theories for political gain. Where other conspiracy theorists might demonize racial or religious groups, however, he focusses on the government he leads. Through social media and the bully pulpit, he has persuaded many Americans to take the same view. Belief in a “deep state” has become pervasive in the United States. In 2018, a poll administered by Monmouth University found that three out of four respondents agreed that “a group of unelected government and military officials” either definitely or probably “manipulate or direct” national policy in secret. Eight in ten people said that the federal government currently monitors or spies on the activities of American citizens. Views about the nature of the deep state increasingly diverge along party lines: a 2019 YouGov poll found that, among people who have heard the term, eighty-three per cent of Republicans thought that the deep state was trying to undermine Trump, while only ten per cent of Democrats did. But the theory is by no means confined to the right. Belief in the deep state is high not just among conservative members of the National Rifle Association but among centrist and left-leaning members of racial minorities, who associate it with the persistence of prejudice against them.

The concept of a deep state is popular, in part, because it is flexible. Conservatives who look askance at QAnon—a lurid theory positing that Trump is combatting a Satanic child-sex-trafficking ring run by Democrats—might use the term to refer to what they see as an overzealous, regulation-loving “administrative state.” Many on the left are less likely to use the term “deep state,” but they fear the military-industrial complex, a “cabal” of generals and defense contractors which they worry pushes the country into endless wars. Many voters in both parties see the politicians, lobbyists, and journalists associated with politics as members of an unaccountable élite focussed primarily on their own interests, not the public’s.