Well, considering Spector said he wouldn't support any of the nominees who were the subject of the Gang of 14 compromise, JRB has a rather massive uphill battle.
Arlen Spector isn't the end all, be all. JRB would be worth a massive battle. I know you feel the same way probably, I'm just stating the obvious.
Specter has to bring the nominee to the committee.
Bush will not appoint anybody who Specter does not support.