Private: Conservative Judicial Activism?

"So Who Are the Activists?" That is the question posed by in a New York Times op-ed piece by Paul Gewirtz, a professor at Yale Law School and Chad Golder, who served as Co-President of the ACS chapter at Yale until his graduation this spring. Gewirtz and Golder write that:

When Democrats or Republicans seek to criticize judges or judicial nominees, they often resort to the same language. They say that the judge is "activist." But the word "activist" is rarely defined. Often it simply means that the judge makes decisions with which the critic disagrees.

In order to move beyond this labeling game, we've identified one reasonably objective and quantifiable measure of a judge's activism, and we've used it to assess the records of the justices on the current Supreme Court.
Here is the question we asked: How often has each justice voted to strike down a law passed by Congress?
...
Of course, calling Congressional legislation into question is not necessarily a bad thing. If a law is unconstitutional, the court has a responsibility to strike it down. But a marked pattern of invalidating Congressional laws certainly seems like one reasonable definition of judicial activism.
Since the Supreme Court assumed its current composition in 1994, by our count it has upheld or struck down 64 Congressional provisions....
We found that justices vary widely in their inclination to strike down Congressional laws. Justice Clarence Thomas, appointed by President George H. W. Bush, was the most inclined, voting to invalidate 65.63 percent of those laws; Justice Stephen Breyer, appointed by President Bill Clinton, was the least, voting to invalidate 28.13 percent. The tally for all the justices appears below.
Thomas 65.63 %Kennedy 64.06 %Scalia 56.25 %Rehnquist 46.88 %O'Connor 46.77 %Souter 42.19 %Stevens 39.34 %Ginsburg 39.06 %Breyer 28.13 %
One conclusion our data suggests is that those justices often considered more "liberal" - Justices Breyer, Ruth Bader Ginsburg, David Souter and John Paul Stevens - vote least frequently to overturn Congressional statutes, while those often labeled "conservative" vote more frequently to do so. At least by this measure (others are possible, of course), the latter group is the most activist.
To say that a justice is activist under this definition is not itself negative. Because striking down Congressional legislation is sometimes justified, some activism is necessary and proper. We can decide whether a particular degree of activism is appropriate only by assessing the merits of a judge's particular decisions and the judge's underlying constitutional views, which may inspire more or fewer invalidations.
...