Willie Nelson Does a Card Trick

In this oddly enchanting video, Willie Nelson performs a card trick known as Sam the Bellhop. In Willie's version, Sam is a nameless porter, but that doesn't matter—Willie's got the routine down cold. Watch, relax, and be amazed:
This comes to me courtesy of MetaFilter, which includes a comment thread explaining the trick. I think you can mostly figure it out on your own, if you noodle on it for a bit. Oh, and that's Bobbie Nelson on the right.