Weiner,” the juicy, exciting, and revelatory new documentary about Anthony Weiner’s 2013 campaign for mayor of New York City in the wake of the scandal that torpedoed his political career, is the story of an addiction — but not the one that you think. Okay, it’s about that addiction too: the one that drove Weiner, as a Congressman, to tweet sleazy messages and photos of himself to would-be groupies. But that’s old news; we hardly need Josh Kriegman and Elyse Steinberg’s enthralling filmmaking to relive the bone-in-the-underwear photo seen ’round the world. As “Weiner” begins, the scandal is behind him (or so he thinks), and the mayoral campaign looms as his shot at redemption.

It’s startling to see the Weiner campaign actually catch fire, igniting crowds of New Yorkers in a way that Bill de Blasio’s did not. It may be part of the primal nature of movies that we get caught up, almost in spite of ourselves, in the whole Comeback Kid scenario, which is fueled by Weiner’s bellicose, truth-telling-in-shirt-sleeves liberal-activist style. The film reports that the driving force behind his decision to leap into the race was his wife and campaign consultant, Huma Abedin (the long-time adviser and right-hand woman of Hillary Clinton, which she still is), who could no longer face being a “pariah.” The campaign was designed to make the scandal into yesterday’s news, and that would happen whether he won or lost. Either way, the couple were spinning themselves into the future.

For a while, it looked like Weiner might win. In his addled and noodgy and finger-pointing way, he’s a born political rock star, and it’s a kick to see his dweeb-on-rye charisma magnetize crowds. He has to deal with constant questions about the scandal, but he brushes them off, and the strategy seems to work. Until, that is, the second wave of scandal crashes down: the breaking news that he continued to do this stuff after his resignation from Congress, after he’d already made a public show of contrition and said, in essence, “I’ll never do it again.” At that point, the air leaks out of his balloon. The issue becomes not sex but lying, the voters turn away from him, and the film starts to play like a Tom Wolfe novel come to life.

It’s here that the real theme of “Weiner” — and the film’s highly charged relevance — emerges. Kriegman and Steinberg brilliantly capture the media house of mirrors, with sound bites magnified into headlines refracted into entertainment inflated into global chatter. The mystery that still surrounds Anthony Weiner’s behavior is: How could he have done it…again? After he’d been caught and shamed? In the movie, the Weiner we see is an actor playing an unrepentant character who may just be himself. Even after that second wave of scandal, he jokes and dissembles and compartmentalizes, referring to what he did as “the thing” or “the dumb thing,” as if he’d been caught smoking a joint or deceiving voters about his taxes. He treats his transgressions as a triviality. After the famous MSNBC interview in which Lawrence O’Donnell asks him. “What is wrong with you?,” Weiner watches a replay of the interview on his laptop, smirking with pleasure at his own defensiveness. He thinks it’s one of his greatest hits! So what is wrong with him?

In “Weiner,” what’s wrong with Anthony Weiner is that he won’t just do anything to save his career. He’ll say and believe anything. He’ll deny, deny, deny — and believe his own denials. His real addiction is to the postmodern maelstrom of media politics, in which every moment is an act of image management, to the point that image management becomes the essence of the campaign, and its substance too. The most fascinating figure in the movie is Huma Abedin, who starts off as radiant and intensely supportive of her husband but winds up skulking in the background of scenes, visibly unhappy at what she calls the “nightmare” they’re going through. Even then, she’s eerily cool, calm, and collected, so the question lingers: Is she talking about a personal nightmare or a political nightmare? Or are they one and the same for her? At one point it’s reported by New York magazine that Hillary Clinton has offered Abedin a Sophie’s choice: either divorce Anthony or recuse herself from Clinton’s budding presidential campaign. The rumor is that Clinton can’t afford that baggage, and it’s easy to see why, since the baggage dovetails with her own.

The dizzying rush of “Weiner” is that the phenomenon it captures — a political culture in which candidates are round-the-clock addicts of image control — becomes, by the end, a powerful premonition of the current presidential campaign. Not that either Hillary Clinton or Donald Trump have a track record of behavior that includes anything like Weinergate. Yet for both these candidates, the issue of transgression and disgrace is central. Hillary has to drag around the ball and chain of her husband’s history with women (and, in the eyes of some, her own enabling of it), which Trump has vowed to make an issue of, and is already doing. And Trump is perhaps the first candidate in American history who’s a walking scandal…by design! However you judge his politics, his what’ll-he-say-next smirking bravura and coiffed pompadour mark him as an Elvis of intolerance; he knows that his king-size moral peccadilloes all work for him. His brand is the crisis of outrage (with a wink). Even minus anything as dramatic as Weiner’s porno selfies, scandal is the air that the presidential race now breathes. Inevitably, the attempt to seize control of scandal oozes into the lifeblood of the campaign, and for the candidates that can’t help but be a compulsive, consuming obsession. It becomes the way that they think. The achievement of “Weiner” is that the movie shows us what that looks like — and the crushing toll it takes not just on democracy, but on reality.