Conservatives usually use "judicial activist" as a code word for liberal. But are liberal judges really more activist than conservative judges? The answer is no. Conservatives judges, at least on the modern Supreme Court, are far more judicially active than liberal judges.
The chart below shows how often recent Supreme Court justices have "legislated from the bench" by overturning existing federal law and regulations. Conservatives loudly claim to abhor such judicial activism, yet the trend is remarkably clear: Conservative justices have been far more willing than liberals to impose their views on the elected Executive and Legislative branches of government. Click on the chart for a larger version:
The chart is drawn from two examinations of the decisions made by recent Supreme Court justices. The first, by Paul Gewirtz, a professor at Yale Law School, looked at how often justices struck down Congressional law from 1994 to 2005. The second, by Cass R. Sunstein, currently at the University of Chicago Law School, compared over 20,000 individual decisions to determine how often the justices overturned federal regulations passed by Executive branch agencies.
To create the chart I averaged the two data sets to create a composite measure of how often each justice overturned existing law and regulations. Justices Roberts and Alito are not included because they haven't been on the Court long enough to collect meaningful data. I first saw these studies mentioned in this Meteor Blades diary on DailyKos; many thanks to him for doing the hard work of digging them out.