Scholars of the U.S. Supreme Court have emphasized two main sources of the court's ability to protect its institutional integrity and ensure compliance with its decisions: public support and the competing ambitions of actors under the separation of powers. These explanations of court authority can be tested through the experience of other countries. After its establishment in 1951, the German constitutional court fit these explanations well. Propositions generated in the American context are thus generalizable. However, neither public support nor institutional rivalries are necessary for courts' authority. Case study methods, as employed here for Germany, are useful in supplementing statistical studies to evaluate strategic theories.