Time magazine lists the reasons that Bush will NEVER get rid of Alberto Gonzales.

I think that the first reason is the most compelling.

Gonzales is all that stands between the White House and special prosecutors. As dicey as things are for Bush right now, his advisers know that they could get much worse. In private, Democrats say that if Gonzales did step down, his replacement would be required to agree to an independent investigation of Gonzales' tenure in order to be confirmed by the Senate.

Without Gonzales at the helm, the Justice Department would be more likely to approve requests for investigations into White House activities on everything from misuse of prewar Iraq intelligence to allegations of political interference in tobacco litigation. And the DOJ could be less likely to block contempt charges against former White House aides who have refused to testify before Congress. "Bush needs someone at Justice who's going to watch the White House's back," says a Senate Democratic Judiciary Committee staffer. If Gonzales steps down, Bush would lose his most reliable shield.

Bush is essentially using Gonzales to construct a wall of interference to keep the Congress from holding him accountable for his many crimes. He is really just playing a waiting game until he leaves office, and Hillary can protect him.