Why does the U.S. Constitution feature separation of powers and protect states' rights? Should the Senate have a filibuster? When can Congress agree on the best policy for the country (and what does "best" even mean)? This course uses a rigorous set of tools including game theory and social choice to help students understand the effectiveness of American democracy to represent diverse interests. Using the tools, we study U.S. electoral systems, Congress, federalism, and the courts, with a focus on understanding how the country has tried to overcome the challenges of group decision making and the inevitable conflicts that arise between the branches of government and divided political interests. Students will leave the course with a deeper understanding of how rules and strategy shape U.S. democracy.