The Ninth Justice blog reports that, according to the Segal-Cover ranking system, Sonia Sotomayor is the most liberal nominee to the Supreme Court in forty years -- the most liberal since Thurgood Marshall in 1967 How could that be?
Segal-Cover rankings evaluate the perceived ideology of judicial nominees by examining how newspaper editorials evaluate their qualifications and ideology. Newspapers have given Sotomayor high marks for her experience -- earning her a 0.8 qualification score. (0 is unqualified; 1 is perfectly qualified.) Yet newspapers have also divided over her ideoloogy -- earning her a 0.79 on ideology. (0 is conservative; 1 is liberal.) For comparison purposes, he scores of other judicial nominees can be seen here.)
Now recall that there have only been two Democratic nominees since President Johnson nominated Thurgood Marshall in 1967 -- Stephen Breyer and Ruth Bader Ginsburg. So, it's possible that Sotomayor could be the "most liberal" nominee without concluding that she's that much more liberal than current justices, at least at the time of nomination. Given the observed ideological drift of Supreme Court justices, to say she's the most liberal nominee is not the same thing as saying she'd be the most liberal justice.
Stony Brook's Jeffrey Segal, who helped develop the system, thinks the focus on the Ricci case and other specific controversies may have played a role. "These scores represent to some extent a fixture on what's current, not necessarily what the court would see," he told Ninth Justice. He also stresses that the system evaluates the perceived ideology of the nominee, and is not a prediction of how a given justice would vote on the Court.
Another possible explanation for Judge Sotomayor's liberal ideology score could be the increased polarization of the Supreme Court nomination process, and the increased attention to judicial ideology in the process. I believe there has been more attention paid to her judicial ideology because more folks on the Right have accepted Senator Charles Schumer's invitation to explicitly consider a nominee's ideology in the confirmation process. As a consequence, it looks as if there will be more votes against Sotomayor than against any Democratic nominee since before World War II.
While I believe Sotomayor is a fairly liberal nominee -- and will be a more reliably liberal vote on most issues than many others expect -- I still do not oppose her confirmation. I remain one of those who believes the Senate should be relatively deferential to a President's judicial picks, focusing on qualifications, character, and temperament, rather than ideology. Thus, even if I believed Sotomayor was the "most liberal" nominee in decades -- and would, as a consequence, be the most "liberal" justice in a generation -- my position would be the same.