The framers of our Constitution established three branches of government but left the details of checks and balances to the future. As chief justice of the U.S. Supreme Court, John Marshall set the precedent for the judiciary’s authority to rule on the constitutionality of laws. In his polemical biography, Harlow Giles Unger focuses on Marshall’s nail-and-claw battles with President Thomas Jefferson. The Sage of Monticello comes off badly in Unger’s account, not only as a slave-owning advocate of the rights of man (which included sex with slave women) but for being a tyrant-in-waiting, pulling almost every trick to advance his power. Marshall is the story’s hero, winning over Jefferson’s appointees to the bench with charm and legal acumen, and holding steady in a political climate teetering on civil war.