Here's Bush's dilemma:
If Karl Rove lied to Bush about his involvement in the leak of Valerie Plame's name, then Bush is protecting a staff member who lied to him, and in addition, Rove is in some doo-doo over the federal false statement statute.
If Rove told the truth to Bush, then Bush is participating in a Nixon-style cover-up.
Not a pretty position in which to be in for C-Plus Caligula, now, is it?
It's pretty clear that Bush simply cannot fire Karl Rove. Rove has had this peculiar doppelgänger relationship with Bush for years, and he knows where the proverbial bodies are buried. If Bush fires Rove, an angry, vengeful Turdblossom could spill a lot of beans the Bush Crime Family doesn't want spilled. Or, he could find himself dead in a bathtub -- another convenient suicide of a Bush family enemy.