If Moore can get the movie into U.S. theaters this summer as planned, the title "Fahrenheit 9/11" could become a rallying cry in the fall election for voters hoping to see Democratic challenger John Kerry defeat President Bush.
"Will it influence the election? I hope it just influences people to leave the theater and become good citizens," Moore said at a news conference Monday. "I'll leave it to others to decide what kind of impact it's going to have on the election."
The movie reiterates other critics' accusations about the Bush family's financial connections to Saudi oil interests and the family of Osama bin Laden. Moore charges that the White House was asleep at the wheel before the Sept. 11 attacks, then used fear-mongering of future terrorism to muster support for the Iraq war.
Yet Moore the provocateur behind the Academy Award-winning "Bowling for Columbine," which dissected American gun culture packages his anti-Bush message in a way that provokes both laughs and gasps.
After making himself the lead figure in his previous documentaries, Moore spends far less time on screen here.
"The material didn't need the help. It was strong enough already. And I feel that a little bit of me probably goes a long way," Moore said. "But the film I feel is clearly in my voice. My voice, my vision, and the way I see things. My sense of humor."
Interviews, mocking footage of Bush's often inelegant speeches, and comments by U.S. soldiers in Iraq many expressing harsh disillusionment in their leaders dominate the film.
It opens with a whimsical recap of the 2000 presidential campaign and the rancor after Florida's photo-finish vote threw the election to Bush over Democratic rival Al Gore.
"Was it all just a dream?" Moore ponders. "Did the last four years even happen?"
The Sept. 11 attacks play out with no images of the planes that hit the World Trade Center and the Pentagon. Instead, Moore fades to black and provides only the sounds of the planes crashing into the towers, before fading in again on tearful faces of people watching the devastation and a slow-motion montage of floating ash and debris after the buildings collapsed.
Moore examines Saudi financial ties to the Bush family and presents post-Saddam Iraq as an economic-development zone for American corporations.
Graver in tone than "Bowling for Columbine," the film includes grisly images of dead Iraqi babies and burned children, along with amputees and other U.S. soldiers injured in Iraq.
Even those skeptical of Moore, who has drawn criticism that he skews the truth to fit his arguments, were impressed.
"I have a problematic relationship with some of Michael Moore's work," said James Rocchi, film critic for DVD rental company Netflix, saying he found Moore too smug and stunt-driven in the past. "There's no such job as a standup journalist."
Yet in "Fahrenheit 9/11," Moore presents powerful segments about losses on both sides of the Iraq war and the grief of American and Iraqi families, Rocchi said.
"This film is at its best when it is most direct and speaks from the heart, when it shows lives torn apart," Rocchi said.
Moore still is arranging for a U.S. distributor. Miramax financed the movie, but parent company Disney blocked the release because of its political overtones.
In the days before Cannes, Moore's Disney criticism whipped festival audiences into a fever for "Fahrenheit 9/11." Hollywood cynics called it Moore's usual showmanship, but when the movie finally unspooled, it earned resounding applause at Monday's press screenings.
"You see so many movies after they've been hyped to heaven and they turn out to be complete crap, but this is a powerful film," said Baz Bamigboye, a film columnist for London's Daily Mail. "It would be a shame if Americans didn't get to see this movie about important stuff happening in their own backyard."
"Fahrenheit 9/11" seems assured of U.S. release, however. Miramax bosses Harvey and Bob Weinstein are buying back the film from Disney and finding another distributor, with Moore hoping to have it in theaters by Fourth of July weekend.
Harvey Weinstein showed up outside the Cannes theater after the first "Fahrenheit 9/11" screening. He declined to speak at length, but as reporters asked if the film would be released, he said, "Have I ever let you down?"
The film takes its title from Ray Bradbury's "Fahrenheit 451," which refers to the temperature needed to burn books in an anti-Utopian society. Moore calls "Fahrenheit 9/11" the "temperature at which freedom burns."
In the film, Moore revisits his hometown of Flint, Mich., whose economic distress after General Motors plant closings was the subject of his first documentary, "Roger & Me."
Moore talks with resident Lila Lipscomb during her daily routine, hanging an American flag in front of her house. He returns later as Lipscomb heart-wrenchingly reads the final letter from her son, Michael Pedersen, killed in action in Iraq.
As her patriotism turns to bitterness against the federal government, Lipscomb journeys to Washington, D.C. Near the end of "Fahrenheit 9/11," Lipscomb stares at the White House and says, "I finally have a place to put all my pain and anger."
For all his Bush criticism, Moore said he would he would like to visit the White House himself.
"I would love to have a White House screening of this film," Moore said. "I would attend it. I would behave myself."