There are two flavors of judicial activism in the U.S. Supreme Court — liberal (e.g., the Warren Court) and conservative (e.g., the current Roberts Court). The NY Times today has an article titled “Court Under Roberts Is Most Conservative in Decades.” This is primarily due to the replacement of Justice Sandra Day O’Connor with Justice Samuel Alito.
A confluence of factors brought Justice Alito to the Court: the failure of the Harriet Miers nomination; the justices’ desire not to have two vacancies on the Court at once coupled with Rehnquist’s desire to hang on and O’Connor’s willingness to resign; the poor health of O’Connor’s husband; Rehnquist’s death.
With Alito replacing O’Connor, the Court has moved further to the right, and the data back this up (though I think how much to the right still remains to be seen). Readers of my former Empirical Legal Studies Blog will be pleased to see that the NY Times cites and uses data from Martin-Quinn Justice Scores, as well as data from Lee Epstein and Harold Spaeth.
Justice Alito was confirmed by a Senate vote of 58-42 (the second lowest vote total in history behind Clarence Thomas). The Democrats could have mustered a filibuster. Should they have? In purely political terms, yes. That said, the next question is a far more difficult one: Should otherwise qualified jurists be kept of the court for political reasons? This depends on one’s view of the role of the Court and the role of the Senate.
(Source of graphics: NY Times, http://www.nytimes.com/interactive/2010/07/25/us/20100725-roberts-graphic.html?ref=us)
JASON J. CZARNEZKI 
July 28, 2010 at 2:08 PM
Should otherwise qualified jurists be kept of the court for political reasons?
I suppose it depends on what you mean by the term “qualified”. If by that you man professional qualifications (which seems to be what you meant), than Alito certainly had those. If instead, you feel that a qualification for serving on the highest court is having a more defensible judicial philosophy (assuming you think Alito’s is not), then Alito would not be qualified.
I’m not sure that we can chalk judicial philosophy up to merely an agreement or disagreement with a candidate’s politics. For instance, no matter what you think of Scalia’s politics, you could certainly take a principled stand against his judicial philosophy, which is an extreme philosophy that only has a very small minority of supporters in the common law legal world. Perhaps such an extreme judicial philosophy would mean that the candidate was not qualified, despite other professional qualifications.
It’s a tough question though, isn’t it?