Mexico on vacation

A guy was traveling through Mexico on vacation:

A guy was traveling through Mexico on vacation when, lo and behold, he lost his wallet and all identification.Cutting his trip short, he attempts to make his way home but is stopped by the Customs Agent at the border."May I see your identification, please?" asks the agent."I'm sorry, but I lost my wallet," replies the guy."Sure, buddy, I hear that every day. No ID, no crossing the border," says the agent."But I can prove that I'm an American!" he exclaims. "I have a picture of Bill Clinton tattooed on one butt cheek and a picture of George Bush on the other.""This I gotta see," replies the agent.With that, Joe drops his pants and bends over in front of the agent."By golly, you're right!" exclaims the agent. "Go on home to Illinois.""Thanks!" he says. "But how did you know I was from Illinois?"The agent replies, "I saw the picture of George Ryan in the middle."