McCain's denial that the visit has anything to do with politics is hilarious (and logic-defying):
"I think the Graham family really transcends politics in America. Billy Graham was an adviser to every president and so I'm not sure that there is any -- there certainly is no political aspect to the meeting that I will have."
McCain has been trying to convince Christian conservatives that he's one of them, and hanging out with the Grahams might help.
Plus McCain and Franklin Graham have a lot of mutual Middle Eastern war-lovin' to discuss. Franklin seemed to welcome the Iraq War as an expansion opportunity for his brand of evangelistic Christianity.