Sonny Landham is running for governor of Kentucky. The former tough guy actor had bit parts in several 1980s movies like Poltergeist and 48 Hours, TV shows like "Miami Vice" and "The A-Team", and even started out in hardcore porn. However, the thing that is most notable about his campaign is that, if he wins, he will be the third actor from Predator (after Jesse Ventura and Arnold Schwarzenegger) to be elected governor.
Also interesting as an additional statistical anomaly is that although all three of them ran under different party banners (Reform Party, Republican Party, and Libertarian Party), not one of them ran as a Democrat (despite the stereotype about actors' political leanings).
EDIT: He ran for governor years ago; his current campaign is actually for the Senate.