By revisiting Thomas Jefferson's understanding of executive power this book offers a new understanding of the origins of presidential power. Before Jefferson was elected president, he arrived at a way to resolve the tension between constitutionalism and executive power. Because his solution would preserve a strict interpretation of the Constitution as well as transform the precedents left by his Federalist predecessors, it provided an alternative to Alexander Hamilton's understanding of executive power. In fact, a more thorough account of Jefferson's political career suggests that Jefferson envisioned an executive that was powerful, or 'energetic', because it would be more explicitly attached to the majority will. Jefferson's Revolution of 1800, often portrayed as a reversal of the strong presidency, was itself premised on energy in the executive and was part of Jefferson's project to enable the Constitution to survive and even flourish in a world governed by necessity.