The President is responsible for the quality of his Administration.
I’ve been reading Tom Ricks’ excellent book about military leadership since World War II, The Generals. In it, Ricks argues that one of the reasons we were able to win World War II was that Generals George Marshall and Dwight Eisenhower were absolutely brutal when it came to relieving field commanders who were not up to the job–and also discerning enough to leave politically incorrect, but brilliant, leaders like George Patton in their positions. He also argues that in the subsequent, cold-war bureaucratization of the military, this rigorous practice has been largely abandoned.
Firing for cause doesn’t seem to exist in the Obama Administration, either. The most high-profile government officials who were removed from their positions over the past five years were the two Air Force generals who were responsible for the sloppy handling of nuclear weapons; Secretary of Defense Robert Gates–perhaps the best cabinet officer in both the George W. Bush and Obama Adminisitrations–ordered both firings.