Finally, a summer movie for readers of this blog:

Swing Vote follows the story of Bud Johnson (Kevin Costner), an apathetic, beer-slinging, lovable loser, who is coasting through a life that has passed him by. The one bright spot is his precocious, over-achieving twelve year-old daughter Molly. She takes care of both of them, until one mischievous moment on Election Day, when she accidentally sets off a chain of events which culminates in the election coming down to one vote … her dad’s.

From the trailer, it looks like Bud’s vote gets rejected by an electronic voting machine and he’s later allowed to re-vote, to break a tie in the decisive state in the presidential election. Realistic? Okay, maybe not, but it looks entertaining.
Don’t miss the regional personality test on the movie’s website (click on “Swing Vote Challenge”), complete with color-coded blue and red maps, which lets you now how you fit with people in your part of the country.