In a new documentary unveiled this week at Michael Moore’s film festival, one filmmaker takes aim at the “vast right-wing conspiracy” Hillary once put on blast. The Brainwashing Of My Dad also warns of how generations of Americans have been tricked into an angry cult-like devotion to a new conservative lord and savior: Rush Limbaugh and Fox News.

Her case study? Her own dad.

Jen Senko first noticed the change in her father sometime during the 1980s when he picked her up from the bus station for a visit home. On the road they passed a Hooters. That’s when the once-gentle Kennedy Democrat and family man started railing against the “feminazis” for protesting the chicken ’n’ cleavage-slingin’ chain.

“I said, ‘Maybe the feminists have a point,’” Senko recalls in her feature-length documentary The Brainwashing Of My Dad, an attempt to understand how the evolution of right-wing media transformed her loving parent into a hostile and isolated fanatic.

His reaction was shocking and extreme, wildly out of character. “He was so mad he threatened to pull the car over and let me hitchhike home,” she says.

It was just the beginning of a sharp change in character that, ex-hippie Senko eventually realized, coincided with her father’s increasing idolatry of the radical right-wing-media and his “hero”: talk radio lion Rush Limbaugh.

Armed with a camera, she began chronicling her father’s rants and antagonistic emails so aggressive his own wife learned to stop talking politics at home. (Years later Senko’s mother slyly deprogrammed the remote controls, weaning her husband off of Fox News.) While actor Matthew Modine (who produced with Adam Rackoff) narrates much of the film, Senko frequently turns the camera on herself and interviews fellow exasperated family members to try to understand what happened.

It began when the filmmaker’s father took a new job that required long commutes and he started listening to right-wing talk shows on the radio on his drives. They turned out to be merely the gateway drug. As Rupert Murdoch’s Fox News Channel took off and ushered in a new era of 24-hour news cycles and rabid punditry, Senko’s dad became more obsessed. He started sleeping in another room, leaving his wife in their bedroom, so he could watch Fox News all night.

Over the years it got worse, particularly in the ’90s. That’s when “it got really bad,” she told The Daily Beast via phone from Michigan, where her film’s first public screening at Moore’s Traverse City Film Festival sold out, prompting a second screening this Saturday. “His entire life became consumed by the agendas that were inundating him on the radio, the television, and through the mail. He joined every radical right Republican organization he could,” Senko said. “Like the NRA—he had never fired a gun in his life! He never hunted, he wasn’t a sportsman. He just got totally bamboozled and signed onboard with everything. It was scary.”

As Senko dove deeper into the mesmerizing and addictive effect that talk radio, Fox News, and radical right blogs had on her father, she started turning to experts to understand how American media had become so sharply unbalanced over the past four decades.

Assembled in Senko’s film are a lineup of media critics and talking heads including Noam Chomsky, CNN’s Reese Schonfeld, progressive talk radio host Thom Hartmann, media critic Jeff Cohen, Media Matters founder David Brock, and Republican political consultant Frank Luntz.

As a result, The Brainwashing Of My Dad isn’t just about one family slowly losing a loved one to ugly political extremism. It’s also a densely packed, sometimes overstuffed examination of how shrewd strategists engineered a long-term takeover of the media on behalf of the GOP, arguing that right-wing think tanks, advocacy groups, and media outlets together achieved what the left has always refused, or been unable, to do: manipulate the minds of America.

With decades of ground to cover, Senko nails some choice sound bites from her interviewees. Luntz, the spin doctor who helped Newt Gingrich twist estate tax into “death tax” and the Bush administration turn global warming into “climate change,” unabashedly reveals how he polls plebes for keywords that frighten them the most and points out how Fox News anchors use hand gestures to subliminally connect with their viewers.

Throughout the film Senko weaves in Skype interviews with people like her, regular folk who “lost” loved ones to right-wing hysteria that tore their family apart. One woman recounts how a heated exchange led to her fanatical uncle pointing a gun at her, before unloading his pistol into the floor. Limbaugh—Senko’s father’s favorite—is singled out for his well-documented history of perpetuating falsehoods to prey on fears over nicotine use, Obama, Muslims, national security, and far sillier claims.

What’s more alarming than his blustery rhetoric, according to the film, is that Limbaugh’s rise to power and influence not only took him into the hearts and homes of millions but also made him and talk radio hosts like him the news source of choice for Supreme Court Justices Clarence Thomas and Antonin Scalia. “Imagine that you’re a Supreme Court justice deciding on things like war and peace, civil liberties, gay marriage, and your window into the world is Rush Limbaugh’s three-hour monologue,” says media critic Jeff Cohen. “That’s pretty damn scary.”

Limbaugh’s fringe-to-mainstream journey coincided with the rise of a larger force in conservative media: Fox News. FNC head Roger Ailes gets plenty of flak, too. (Reps for Limbaugh and Fox News did not respond to The Daily Beast’s requests for comment.) Reese Schonfeld, co-founder of CNN, recalls how Ailes helped birth what we now know as the modern right-wing media. “He didn’t know much about news,” Schonfeld assesses. “I’m not sure he knows much about news now—but he knows television, and he’s a great propagandist.”

Pundits outline how stories built on alarmist language and misinformation start at the bottom, picked up from the Internet or uncorroborated reports, before Ailes throws it into the day’s Fox news agenda at his morning meetings. “They air the stories and start to bang the drums that the mainstream media is censoring and won’t report to try to pressure and guilt the mainstream media into following their lead,” blasts Media Matters’ Brock. “The existence of Fox News and having that conservative propaganda stick—and false and wrong approach to journalism out there—has a toxic effect on the rest of journalism, to the extent that other journalists follow the Fox lead.”

Those brightly colored sets and disorienting camera movements? They’re designed to throw the audience off-kilter, the film argues, so that the anchor du jour can be a centering force, the voice of authority setting you on solid ground. Cohen recalls being in the green room at Fox News, watching a clearly skewed story airing on the monitors as producers, staff, and other contributors watched. “Someone said, ‘Wow, that was really fair and balanced!’ and the whole room erupted in laughter,” he remembers.

Senko says the problem is only right-wing media are using these kinds of tricks. “Centrists and liberals and progressives have to wake up and smell the fucking coffee,” she told me. “We’ve all sort of been polite. Liberals, progressives, we want to be fair—but it’s not about being fair, it’s about being objective. So I really hope to make people aware of this. Oh my God, it’s the media, stupid.”

Her hope is that the film, which screened as a work in progress, gets in front of audiences in time to make a difference in the 2016 presidential election. Senko, incidentally, calls herself a Progressive and is throwing her weight behind Bernie Sanders. “I’m tired of seeing Democrats allowing themselves to be slapped in the face, allowing and adopting the language that people like Frank Luntz came up with for the Republicans,” she said. “Just being aware is a huge step. It’s going to change conversations.”

To that end, Senko’s film takes a fiercely unapologetic stance; at one point, she invokes a quote by Nazi propagandist Joseph Goebbels in an archival montage of conservative news anchors linking WMDs to Iraq. “Goebbels actually did look at American advertising to get ideas for propaganda, so there’s a tie-in there,” she said. “I guess it’ll rock some boats, but I feel like it’s accurate and I stand by it.”

Senko says she reached out to Limbaugh to participate in the film “several times” but got no response. With Ailes, she didn’t bother asking. “We knew we wouldn’t have a shot with [Ailes] because he’s very secretive and he’s somewhat paranoid,” she admitted. “I really didn’t want to bring his attention too much to the film, because it’s actually a little bit scary. I didn’t want to go, ‘Hey! Over here!’”

Now that the film’s out in the world, she’s been bolstered by initial reactions but is still bracing for a right-wing backlash. “I feel like I’m waving a flag in front of a bull. I’m scared. I am a little scared.”

As for Senko and her now-elderly dad, they’re back on good terms these days. She hopes sharing their story gets more families like hers talking over the dinner table, bleeds over into the election, and injects a healthy dose of skepticism into the lives of the Limbaugh-worshiping dittoheads and Fox News addicts of the world.

“Maybe groups will decide they want to bring back the Fairness Doctrine. Maybe there will just be a common knowledge among people that saw the movie and the next time somebody says something [citing right-wing media] they’ll say, ‘They lie. They make stuff up,’” Senko muses. “A lot of times people are intimidated and don’t want to get into a confrontation. Maybe people will fact-check their media more. Maybe the people who watch Fox News will be a little bit ashamed and think, ‘Maybe it is a little closed-minded of me to have one source.’”

“There are so many possibilities that I hope for.”