On judicial activism
A few months ago, the New York Times published an op-ed on who the real activists on the Supreme Court are.
To measure this, they looked at how often each judge voted to strike down legislation passed by Congress. Here's the breakdown:
Clarence Thomas 65.63 %
Anthony Kennedy 64.06 %
Antonin Scalia 56.25 %
William Rehnquist 46.88 %
Sandra Day O’Connor 46.77 %
David Souter 42.19 %
John Paul Stevens 39.34 %
Ruth Bader Ginsburg 39.06 %
Stephen Breyer 28.13 %
Historically, courts will often defer to Congress on many issues that come before them. In such instances, they cite that the matter is a "political question" and not for the court to decide.
Certainly some laws passed by Congress are unconstitutional, and it would be irresponsible for a justice to never vote to overturn a law. It's more about the pattern here, and how eager the justices are to subvert the will of Congress and the people. Looking at the data above, it's the conservatives who tend to legislate from the bench and not the moderate to liberal justices.