Only twenty-five years after its founding, the Federalist Society today boasts a nationwide membership including renowned attorneys, politicians, policy makers, and jurists. Although the Society maintains that it is not a political organization, liberal political activists claim the Society has long pursued an ambitious—and extremely conservative—political agenda. In this article we ask: do members of the Federalist Society decide cases in a more conservative manner than other nonmember jurists? Using data on decision making in the U.S. Courts of Appeals, we find Federalist Society members are significantly more conservative than nonmembers and examine the long-term implications of our study.