There's a book that explains it all called "Bush's Brain."
http://www.amazon.com/exec/obidos/ASIN/0471423270/
Karl Rove is the manager of all white house and slipstream media (Limbaugh, O'Reilly, Drudge) 'talking points.'
He redefines 'dirty tricks,' having masterminded, as Bleyseng mentioned, the defeat of McCain with a 'whisper campaign' in the primaries.
By many accounts, a real scumbag.