Like most documentaries, the new film about Sarah Palin that premiered in June in Minneapolis is ostensibly about the past. Mostly focusing on Palin's political career in Alaska, "The Undefeated" portrays a crusader clashing with the governing GOP establishment and big-oil interests -- fights that earned her the highest approval rating of any governor in the country at the time.

Of course we all know "The Undefeated" is really about the future. Of Palin's political prospects in 2012, sure. But more important, said the documentary's director, Steven Bannon, the film allows Palin to redefine herself. "The meme was so set that this woman was an airhead, a bimbo, 'Caribou Barbie,' a Christianist ideologue -- when the evidence was there that she was actually an engaged executive."

To Bannon and others in the film who ideologically identify with him, the thieves in this political whodunit have as many right-handed fingerprints as left-handed.

"The thing that should be shocking here is not that the left went after her, but where was the air cover?" Bannon asked. "No one in the Republican establishment came to her defense." Accordingly, he said, "This film is as controversial on the right as it is on the left."

Not that Bannon spares the left. Barely before viewers can get their first handful of popcorn, pop culture artists paint a picture of the former Alaska governor and 2008 Republican vice presidential candidate that startles in its intensity. A quick-cut collection of cut-downs from movie and music stars, comedians and others attacking Palin politically and personally are remarkable, even in the context of today's coarse culture.

The montage then morphs into video images of a different sort: Home movies of a young Sarah, smiling, laughing and camera-hamming, just as most kids that age would.

The vivid differences were carefully planned, Bannon explained.

"The pop culture beat-down is first. I'm trying to take you on 'Dante's Inferno.' That's not a media beat-down. I don't have [Keith] Olbermann and [Katie] Couric and [Chris] Matthews and [Rachel] Maddow, because to me that's just part of the process."

The process went well beyond punditry, Bannon believes.

"It's the intensity of the hatred and vulgarity, the graphic violence that's displayed, and the portrayal of her son Trig, the mocking of an innocent special-needs child" that gets audiences angry. He added: "I want them angry."

But most who will see "The Undefeated" are already angry about what they consider media mischaracterization of Palin. And that's the film's challenge: If it simply preaches to converted Palin-backers, it won't accomplish Bannon's goal of "setting the record straight."

"I did not make this movie for Palinistas," Bannon said. "They know this story. They're tangential to what I've done here."

The problem for "The Undefeated" is that experts who study political communication agree that theatrical release might mitigate the movie's impact.

"From the beginning of the documentary film as an entity, filmmakers have been motivated to bring issues to broader attention, and to bring the basis for some kind of change in understanding, and some kind of action," said Michael Renov, professor at the USC School of Cinematic Arts. But, he said, "All of it is variable and depends on what's the distribution platform: Is it television, theatrical release, union halls, or schools or community centers?"

As for forking over 10 bucks at the cineplex, "There aren't very many people who go to these things who aren't already converted," said Kathleen Hall Jamieson, professor at the Annenberg School for Communication at the University of Pennsylvania. "So the effect is not persuasion in the classic sense, it's reinforcement. But that is extremely valuable because it has an energizing effect."

Jamieson points to another documentary, Michael Moore's anti-Iraq-war film "Fahrenheit 9/11," as an example of the media-political dynamic of documentaries. It is the top-grossing documentary of all time, and its $119 million box office take made it a blockbuster by any standard. But in the ranking Moore really was shooting for -- electoral votes -- "Fahrenheit 9/11" didn't prevent the reelection of President George W. Bush.

Annenberg's National Election Survey was used by Talia Stroud, a professor at the University of Texas, for her book "Niche News." "Fahrenheit's" effect was to "reinforce -- or polarize -- people's beliefs," said Stroud, who calculated that "those with unfavorable impressions of Bush were more than six times more likely to watch the film. And those with favorable impressions of Bush opted to spend their money elsewhere."

Like all artistic expression, documentaries don't exist in a vacuum, said Jamieson. "It depends on what is seeping into the popular culture. In 'Fahrenheit 9/11' what seeped in was controversy regarding facticity. So in the broader culture the message is 'yes, go and see it, but don't believe all of it.'"

And consider context, said Michael Griffin, a visiting professor at Macalester College who teaches a course in documentaries. "A film's impact doesn't depend on just what happens on the screen, but on the political and social context of attitudes in which it appears."

As a conservative, Bannon was an unlikely attendee -- let alone admirer -- of Moore's movie.

"I don't agree with any of Michael Moore's politics, but I think he's a master craftsman. I think his films are brilliant," he said, adding that if not for another notable (if not notorious) political video, the "Swiftboat Veterans for Truth" ads, Sen. John Kerry would have been elected.

Bannon can only hope others are similarly open-minded about his film. It's not likely, said Griffin. "A film about Sarah Palin, who is someone who is already a polarizing figure, and someone who has hard and rigid divisions between those who like her and don't like her, won't have a big impact on changing the landscape of support for her."

And yet, as "The Undefeated" details, Palin's career has been defined by beating expectations. However unlikely, there is always a chance of art imitating life.

The Rash Report can be heard at 8:20 a.m. weekdays on WCCO Radio, 830-AM. Follow John Rash on Twitter: @rashreport.