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 -- 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.
And keep in mind that the "marking period" here was 1994-2005, so they were overturning laws written by Republicans.
So let's cut through the bull. The Republicans actually like activist judges -- when they're Republican. When they screech "activist", run it through your Bullcrap-To-English dictionary and they really mean "Democrat".