How can you answer that question if the other candidate wouldn't have been confirmed? If he can't get them on the Court, why could they possibly be "better" than O'Conner?
Are you saying that Bush made the decision to go with a mediocre candidate rather than taking the risk of not being backed up by the Senate?
No, I'm saying that he nominated a candidate who is absolutely positive will NOT "drift" once she gets on the Court -- one that will definitely take the Court rightward.
If that's the case, I think it's a bad choice by Bush - I'm not as convinced as you are that it wouldn't be doable.
I'm positive he couldn't have gotten anybody else confirmed with the way the Gang has screwed him; I believe he's going to get another shot at the Court and after Miers is on the Court, you're going to see the next nominee blow the Democrats' collective peabrains; but I don't think it will be anybody who has already been named/listed.