Over the years, Kevin Costner has made a pretty solid career for himself playing the All-American good guy: a good-guy farmer in Field of Dreams, a good-guy Civil War vet-cum-Native-American-lover in Dances With Wolves. He even played the squeaky clean Eliot Ness in The Untouchables.

Sure, he has taken on his fair share of darker parts, particularly of washed up men of one form or another who have failed to cope with life's curveballs. But somehow, it is his inner corn-fed nice-guy quality -- the one that caused Madonna to diss him lo those many years ago when he visited her backstage after a show in her Truth or Dare concert doc -- that sticks.

Costner tries once again to challenge that paradigm and get in touch with his inner slob in Swing Vote, in which he plays Bud Johnson, a lazy factory worker from rural New Mexico more interested in drinking his next beer than he is in getting down to the polls to vote. Bud is the ultimate apathetic free-rider. How perfect, then, when it turns out that after a computer error, not only does his vote count, but in fact it will be the deciding vote in the entire national election?

"Clearly Swing Vote's not a public service announcement," Costner says about the 'get out and vote' message inherent in the movie. "But I think it might be better than that because it doesn't preach, it doesn't hit you over the head. Everyone one of who you sit in the dark and get to the end, and you can ask yourself a fundamental question: 'Am I Bud? Or am I a participant? And who am I going to be going forward?' And it's not going to change the world, but I feel good about what we tried to do."

In addition to starring in the movie, Costner also takes a producer credit. And his band, Modern West, also makes an appearance. "I think you forgot we financed it, too, [my wife] Christine and myself," he adds jovially. "This movie wasn't going to be made because it was determined that it didn't have an upside economically in the foreign markets. And I wasn't going to argue."

"Our standing in the world community is such that it was argued 'No one wants to see a movie about an American election' because a lot of people aren't very happy with us," he continues. "But I had the same thing thrown at me with Bull Durham. It didn't have an up-side. Field of Dreams didn't have an up-side. But I don't think that's reason enough to not make a movie, so I did wear a lot of hats and one of them was committing financially to making the movie just because I thought it had a chance to be classic if we ran its edge."

By edge, Costner means the even-handed nature with which writer Jason Richman and co-writer/director Joshua Michael Stern skewers the politicians on both sides of the aisle, playing in this movie by Kelsey Grammer and Dennis Hopper. "They didn't have to demonize either party to make their point," he explains. "They were able to take hot button issues like immigration and gay rights and abortion, things where you can actually lose your friendship over a dinner table sometimes, and actually have you all laugh. You got it."

As a political movie, one would think that it was planned to come out in an election year. But maybe that isn't such a good thing? "I thought perhaps we would be dealing with voter fatigue by now," Costner says. "Maybe people would just be going, 'Enough already. I want to see another superhero. Get it up there as quick as you can!'"

"But, I can't see it as a negative now," he continues. "I think maybe it could help us. We need help. We're a $20 million movie existing out there among those tsunami movies. I mean, we have way more action than The Mummy, and I just can't understand why people aren't talking about it," he jokes.

More than that, though, Costner thinks this movie isn't just relevant because of the upcoming election. "If the movie hinged on it, I knew that I didn't have a good movie," he explains. "This movie, I think, could be relevant five years from now just because of its entertainment value, its comedy. But more importantly, it's got an emotional bottom that I think is nice to revisit. I've talked to a lot of people, a lot of men actually told me they got choked up. And I think American cinema is at its best when certain things happen -- obviously of a positive nature -- that you didn't anticipate. In a way, that's gettin' your money's worth."

Swing Vote opens nationwide on August 1, 2008.