It is the right of center folks that make things happen in the republican party. They are very very skeptical of Miers, and some are openly hostile.
The difficulty for the White House is that they have relied on the right of center network to advance, move, deliver...or whatever you want to call it----almost all of the issues important to GWB. FOr the most part--these networks are not there this time.
Frankly---if the White House could fire up there super secret computer spy machine and search all of the e-mails on the right with the words "Miers", "Withdrawal" and "Pool" they would be even more depressed.
It seems to be McCain, though, who makes things happen in the Senate! ;-)