I still don't see it that way. Granted, the dems can't manage to damage or stop the Roberts nomination regardless of who he is replacing. The inevitable "fight" was and is going to take place on the 2nd nomination anyway, so it doesn't really matter.
Agreed. But being able to spin the 2nd nominee as a Rehnquist replacement paves the way for an easy confirmation for a conservative. Having GOPers being able to go out and say this is just a conservative for a conservative is a huge plus and it kills the Democrat arguement that this is going to change the balance of the court. The GOP will simply be able to say it does not, it is a conservative for a conservative.