The U.S. Constitution sets out a system of government with distinct and independent branches—Congress, the Presidency, and a Supreme Court. It also defines legislative, executive, and judicial powers and outlines how they interact. These three separate branches share power, and each branch serves as a check on the power of the others. “Ambition must be made to counteract ambition,” James Madison explained in Federalist 51. Why? Madison believed that the Constitution’s principles of separation of powers and checks and balances preserve political liberty. They provide a framework for freedom. Yet, this framework is not self-executing. We the people must continually act to ensure that our constitutional democracy endures, preserving our liberties and advancing our rights. The Law Day 2018 theme enables us to reflect on the separation of powers as fundamental to our constitutional purpose and to consider how our governmental system is working for ourselves and our posterity.