If you’re looking for an answer, just look to Roger Clegg, who has written a great question-and-answer article on the topic for the Committee for Justice.
Clegg is president of the Center for Equal Opportunity, a former high-ranking Justice Department official, and one of the nation’s leading experts on civil rights law.
Here’s a sampling of what you’ll find at the Committee for Justice:
Q. What is judicial activism?
A. Judicial activism is when a judge ignores what the text of the Constitution or some other law says and substitutes instead his own preference for what it ought to say. It can involve putting something into the text that isn’t there, or taking out something that is there.
Q. Is it activism whenever a court strikes down a statute as unconstitutional?
A. Of course not. If a statute violates the Constitution, it would be judicial activism not to strike it down. Striking down a statute is judicial activism only if the statute really isn’t inconsistent with the Constitution.
Q. Is it activism whenever a court overrules one of its own precedents?
A. Again, of course not. The principle of stare decisis – Latin for "Let the decision stand" – is a venerable one, and there are good reasons for courts not lightly to ignore their past rulings. But from time to time they do so, and it really doesn’t make sense to call it judicial activism when they do. After all, how can overruling a decision that was itself activist be properly labeled activist?