The right-wing campaign consultants who brought negative advertising, mud-slinging, and — let’s call it what it is — lying into the center of the American media ecosphere used to keep themselves out of sight. That was part of their mystique: They plied their trade from the shadows. (It’s part of what gave their lies power — that the lies seemed to emerge from the ether.) In the ’90s, though, documentarians and TV news divisions began to shine a light on people like Lee Atwater and Karl Rove and the way they conjured their media voodoo. Richard Nixon’s dirty tricksters paved the way, but these were the new visionaries of the attack-dog political culture; they were the rock stars of fake news. (It’s no accident that Atwater was literally a blues-rock guitarist — his whole ethos was to make scorched-earth campaign tactics seem wild-ass and cool.)

Yet when you watch “Get Me Roger Stone,” the lively, fun, sickening, and essential new documentary, you realize that Atwater and Rove may have excelled at what they did, but there was — and is — only one king. That’s Roger Stone, the man who arguably put Donald Trump in the White House.

He’s a dark genius of branding, so it’s no surprise that Stone presents himself as a full-on character: a cigar-smoking, martini-swilling grandee with an aging bodybuilder’s physique tucked inside chalk-stripe suits, a rigid line of swept-back white hair (even his follicles look ready for battle), and — as he’s always proud to display — a tattoo of Richard Nixon’s face on the middle of his upper back. His real armor is his total lack of shame, which echoes that of Trump. Relative softheads like Atwater and Rove tried to shroud what they did in a cloud of euphemism, but if you call Roger Stone a liar, a cutthroat, a slimy prince of darkness, or anything else, after saying “Thank you” he’ll reply with utter implacable calm that the fact that you hate him so much is the proof that he’s done his job well. You can’t argue with a man like this. You can only listen to him (or vote against his candidate).

Dylan Bank, Daniel DiMauro, and Morgan Pehme, the co-directors of “Get Me Roger Stone,” do a lot of listening, and a lot of fascinating filling in of background. But by zeroing in on the ultimate inside outlier of conservative politics, they tell a larger story: of how the Republican Party made itself over from an organization of gentlemen into a slash-and-burn cult.

Early on in the film, the New Yorker writer Jeffrey Toobin calls Stone “the sinister Forrest Gump of American politics,” adding that “He’s not just this single-minded guy but this Machiavellian, almost crazy guy who shows up at every key moment in recent American history.” He was there for Nixon, Reagan, Bush I and II, and, of course, the Trump campaign, which Toobin calls “a pure Roger Stone production.” He means that Stone guided the optics and, to a large extent, the attitude, going all the way back to Trump’s obsession with the “birther” issue, which he got from Stone (and which is really what put his candidacy on the map).

Stone was 12 when he watched Barry Goldwater take the Republican nomination in 1964, and he seized on the power of that moment and never looked back. He angled his way onto the 1972 Nixon campaign when he was just 19, with buck teeth and a geeky shock of receding hair (which he soon died dandyish blond), and after receiving payouts from the CREEP slush fund he was mentioned, briefly, in the Watergate hearings. Most people saw Watergate as Nixon’s great sin, but for Stone it was the dirty tricks of the Nixon campaign that formed the basis of his political vision. Though he claims (with a wink) to act within the letter of the law, his philosophy became: Do whatever it takes.

In “Get Me Roger Stone,” Stone is Forrest Gump as a social-climbing Republican weasel. He learned from the best, getting chummy with Roy Cohn, the infamous back-stabbing lawyer and fixer, and becoming a force in the rise of negative advertising. Then, just in time for the Reagan era of corporate influence-peddling, he joined the launch of Black, Manafort, Stone, and Kelly, the original firm devoted to big-money lobbying. It established its infamy — and the ethos of the new age — by taking on as clients some of the world’s worst dictators, who were looking to soften their image as torturers. Years later, Donald Trump rose to the presidency by pledging to “drain the swamp,” but it’s no coincidence that Stone, who was Trump’s image guru, more or less invented the swamp. He and Trump never had much interest in draining it. They just papered it over with “populist” rhetoric.

Stone, in a clip, calls politics “show business with ugly people.” Many observers, going back to Robert Altman in his 1975 masterpiece “Nashville,” have grasped that American politics was turning into showbiz, but Stone took that notion and pushed it to the wall, embracing the corruption of politics-as-performance-art so completely that he turned himself into a new kind of hack: a postmodern image manipulator. It’s no wonder that he’s equally comfortable rubbing shoulders with Alex Jones, the conservative conspiracy wing-nut who makes Fox News look like the PBS Newshour, or with nude marchers in the Gay Pride Parade.

Years ahead of his time, Stone grooved on it all: the celebrity-based media politics, the sleaze, the ruthlessness, the making s—- up. He first tried to get Trump to run for president in the late ’80s, and after seeing how Ross Perot’s third-party candidacy had allowed Bill Clinton to win the presidency, in 2000 he brought Trump into the middle of Patrick Buchanan’s Reform Party bid precisely so that it would fail. The movie suggests that Stone was behind the bogus George W. Bush draft-dodging letter that brought down Dan Rather and, in the process, helped to defeat John Kerry. During the Trump campaign, Stone sported a T-shirt with the word “Rape” under Bill Clinton’s face.

With Roger Stone, the hits keep comin’, but “Get Me Roger Stone” captures how he became the renegade of right-wing image manipulation because, in part, of how he’d lost his own respectability through scandal. In 1996, when he was in the midst of guiding Bob Dole’s campaign (which made a point of tweaking Clinton for the immorality of his extramarital affairs), Stone and his wife were outed as swingers, with embarrassing photographs in magazines. He was drummed out of the Republican establishment, and from that point on he had to consult off the books, which only drove him to more extreme and unsavory tactics, since he was no longer beholden to the party.

By his own admission, the Roger Stone we see in “Get Me Roger Stone” is a role he cultivates. He is charming, light-witted, outrageous. The movie is divided into sections marked by Stone’s Rules (“Past Is F—ing Prologue,” “Hate Is a More Powerful Motivator Than Love”). Stone doesn’t appear to take politics too seriously, and on the surface there’s something appealing in that. But, of course, what the politics of Roger Stone teaches you is that you can never believe the surface. It’s all a mirage. He has spent 45 years inventing the world as we know it — or, you might say, he has spent those years waiting for the world to catch up to him. Now that it has, and it’s Roger Stone’s world and we just live in it, it’s time to fight back or be very afraid. Or both.