Not just the year's most riveting documentary film, "Trouble the Water" -- which follows young Hurricane Katrina survivor Kimberly Rivers Roberts in her amazing efforts to rebuild her life -- is also a stirring rebuttal of the "objectivity" mandate in news reporting.

"We made this film because we want to impact the public conversation and influence lawmakers," said co-director Carl Deal in St. Paul, where he attended an Impact Film Festival screening of "Trouble the Water" on day 4 of the Republican National Convention.

The documentary, playable to both sides of the political spectrum, had also been screened at the Democratic National Convention, courtesy of the bipartisan Impact.

"In Denver, we had the room filled with a lot of delegates," Deal said, "which was exactly what we wanted."

The movie's fortunes haven't always been so great. Deal -- who, along with fellow New York-based documentarian Tia Lessin, began making the film just after Katrina struck in 2005 -- said it has been a fight to get "Trouble the Water" to theater screens.

"Early on, industry people said things to us like, 'We don't know how to market this film.' They talked about the viewing public having 'Katrina fatigue,' which is coded language for the pain we feel over having to confront how America treats its citizens in poor communities all over the country," Deal said.

He and Lessin had gone to New Orleans thinking they'd make a film about the work of National Guard members brought to the Gulf Coast from Iraq. At a Red Cross shelter, they were approached by Roberts and her husband, Scott, who told the filmmakers they had some camcorder footage they were looking to sell. Deal said he knew immediately that he and Lessin had a new story to tell.

When speaking of Roberts, whose astonishing eye-of-the-storm images figure prominently in the film, Deal was effusive in his praise.

"Kimberly has enormous internal resources, and she's always thinking outside the box," he said. "When the storm came, and she and her family were pushed into the attic, she realized she could be making a document of how she would die. Her footage is certainly not the Katrina we saw on television."

The Robertses had planned to appear with Deal in St. Paul. But as history seemed to be repeating itself in the form of Hurricane Gustav -- and in political promises of rescue aid -- the pair was compelled to attend to Gulf Coast relatives in need.

In their place, Rep. Keith Ellison (D-Minn.) took part in a postscreening Q&A session at the Landmark Center. "Katrina is not over," he said. "We know it here in Minnesota, where several Katrina refugees came and have decided to stay, even though they'd like to go home to New Orleans."

Sharing the Landmark stage with Deal, Ellison congratulated the filmmaker on his work.

"Nothing highlights these issues of racial and economic justice more strongly than art," he said. "I think it's critical that art and politics come together to address the needs of people."