A very interesting Op-Ed contribution in the NY Times today. The authors measure a judge’s activism by his or her willingness to strike down federal laws. Looking at the court’s actions since 1991, 64 cases are considered in which the constitutionality of laws was at stake. The authors then examine the percentage of time that each justice voted to overturn the given law. The results: The most activist judges are Thomas and Kennedy, with Scalia not far behind. The least activist judges: Breyer, Ginsburg, and Stevens. Sitting in the middle are Rehnquist and O’Connor, with Souter slightly less activist than those two.

It’s not a perfect measure, certainly, but the results are entertaining. As the authors point out, by their measure, activism is not necessarily a bad thing. The question then becomes: What level of activism is appropriate for a Supreme Court justice? Too much activism, and the judges are thwarting the will of the people’s democratic representatives. Too little, and they may be inadequately defending the constitution.