How about this:
"Dan Rather was replaced by a robot some time ago-- but the RNC hacked into his programming and made him run the story??? Anybody? Anybody?"
Nah, Karl Rove used a time machine to an ANG office in the early 70s and provided them with a modern computer with M.S. Word. After the memos were created, he took the computer back to hide the evidence.
I know this because its the only way that the documents could be both authentic and at the same time a dirty trick by Karl Rove.