Sounds like a nice idea for a movie, or one produced back when people thought politicians had integrity and decency....but I'm a sucker for those when they're done right.
If you're talking about the movie with Henry Fonda (playing a presidential candidate) then it's a decent flick. I don't remember many of the details but it's about a presidential election with Fonda playing a basically decent guy running against a real bastard (and for the life of me I can't remember the actor's name and I'm too tired to look it up).
