Proud pop Bill Clinton discusses Chelsea's wedding with David Letterman

Former President Bill Clinton is thrilled at his daughter Chelsea's marriage for a number of reasons -- including the fact that he now has another guy in the family.

"My main goal was to have a chance," he joked with David Letterman on "The Late Show" Monday night (Sept. 20). "Hillary wanted this to happen because she wants to be a grandmother more than she wanted to be president."