So why is Karl Rove still employed in the White House?

Trying to justify his authorizations of illegal surveillance, Bush said in his radio address on Saturday (President's Radio Address 12/17/05):

Revealing classified information is illegal, alerts our enemies, and endangers our country.

Given the role we know Karl Rove played in outing Valerie Plame, why hasn't Bush fired him?  Why has his security clearance not been revoked?

I can't believe after the way Bush has handled the Plame case that he would say something like this.