I've seen a number of diaries championing various people for nomination, often based on their liberal credentials. They all sound great. I'd love to see Justices Clinton, Clinton, and Gore in the next three years if just to make some heads explode.
But one thing I think people are forgetting is just how independent people with true integrity can become when appointed to the court. For every Roberts, Scalia, and Thomas, there are judges that surprise people.
Many headlines call Stevens the most liberal judge, but he was appointed by a Republican, Ford. O'Connor was appointed by Reagan and progressives have generally considered her liberal or at least a voice of reason. Burger and Blackmun were both appointed by Nixon, and yet Burger ruled against Nixon and in favor of some abortion rights, surprising conservatives. Blackmun wrote Roe v. Wade and the Dissent and Bowers.
I'm sure that some "liberal" judges had switched teams as well. For some people, a funny thing happens when they are appointed to an independent position for life. They start to think for themselves instead of for a party. It's rare, but there are actually people out there with integrity.
I very much doubt that Obama will appoint a liberal or a progressive judge. That just isn't the kind of person he is. I imagine many people here will be supremely disappointed in the person he does nominate, myself included, because of conservative views on finanaces or government spying/secrecy. My hope is that he will appoint somene because of his or her ability as a legal scholar and integrity, not because of pure political considerations.
It seems in my small amount of research, it seems historically more likely that a conservative appointed justice becomes more liberal than the reverse, but I would welcome examples of the reverse.
In the meantime, lobby for a progressive or liberal nominee, but don't spurn a middle of the road choice or give up, especially at the polls this fall.