Rather has it in for all Republicans but especially the Bush family. Bush 41 did humiliate Rather in 1988 and he has never forgotten...unfortunately for Rather, GWB has never forgiven Rather for the way he visciously attacked his father. Let the games begin. I'll put my money of the current President Bush.
IMHO, the President is doing everything he should be doing --- he's staying out of the way while Rather's reputation is flushed away.