According to the Washington Post, the only reason Gonzales still has his job is because of President Bush's loyalty to old friends:
Bush does not think Gonzales did anything wrong in dismissing the prosecutors, according to aides, but has been aggravated by his friend's clumsy, shifting explanations of what happened. In effect, advisers said, Bush is giving Gonzales a chance to fix the situation today.
What happens if he does not remains unclear. No one in the White House believes Gonzales can say anything that would get Democrats to drop the matter, but his supporters hope he can be confident and consistent enough to explain his role without providing more ammunition for critics. Should he stumble, some Republicans said, Gonzales has a responsibility to fall on his sword, sparing Bush having to ask.