If Bush has been thinking about this for awhile, then I would begin to understand why he replaced John Ashcroft (never did understand that one). In nominating John Ashcroft, it would make the "extreme nomination" complaint unpalatable as he was a fine Attorney General for the US and he was also ONE OF THEM for 6 years prior to AG. To me, John Ashcroft IS the Supreme choice....
The problem with putting up Ashcroft, Gonzales, and to a lesser extent Olsen, is that if the were confirmed to the SC, they would be required to recuse themselves from any case that they had advised on in their previous jobs. Bush is not going to propose any of those guys.
My guess? Garza, Roberts or Brown. But I'll be completely unsurprised if it's another judge who approximates their views. One thing I'm absolutely certain of; George is not going to put up any kind of moderate. Does anyone really think he's that foolish?
(Aside from the One Issue Monomaniacs here, of course.)