After the collapse of communism, some thirty countries scrambled to craft democratic constitutions. Surprisingly, the constitutional model they most often chose was neither the pure parliamentary model found in most of Western Europe at the time, nor the presidential model of the Americas. Rather, it was semi-presidentialism--a rare model known more generally as the "French type." This constitutional model melded elements of pure presidentialism with those of pure parliamentarism. Specifically, semi-presidentialism combined a popularly elected head of state with a head of government responsible to a legislature. Borrowing Constitutional Designs questions the hasty adoption of semi-presidentialism by new democracies. Drawing on rich case studies of two of the most important countries for European politics in the twentieth century--Weimar Germany and the French Fifth Republic--Cindy Skach offers the first theoretically focused, and historically grounded, analysis of semi-presidentialism and democracy. She demonstrates that constitutional choice matters, because under certain conditions, semi-presidentialism structures incentives that make democratic consolidation difficult or that actually contribute to democratic collapse. She offers a new theory of constitutional design, integrating insights from law and the social sciences. In doing so, Skach challenges both democratic theory and democratic practice. This book will be welcomed not only by scholars and practitioners of constitutional law but also by those in fields such as comparative politics, European politics and history, and international and public affairs.