Is the Federal Constitutional Court, as often depicted, a mostly independent actor in the German political system? The present analysis shows for the first time to what extent public opinion has a systematic influence on the decisions of the Federal Constitutional Court. Our evidence is based on the analysis of abstract judicial reviews and federal-state disputes in the period from 1974 – 2010. We show that the Federal Constitutional Court is more likely to rule in favor of the opposition, the stronger the public supports the specific substantive position of the opposition. Two mechanisms that could bring about this correlation are finally discussed. While the court does not blindly follow public opinion it will nevertheless consider the acceptance of its decisions as an important source of legitimacy