It sounds as if Max Cleland would be an "unimpeachable" source and someone that CBS would want to protect. They are thinking long and hard before giving up the amputee. Therefore it does have DNC connections.
Cleland would seem more likely worth protecting. Dan would be more (in my opinion) willing to hold the tough line for him and memo's chain of custody. If this does get attributed to the DNC it would be a total disaster for the party. Maybe Zell can lead the way for the new new Dems (wishful thinking).