This summer, the U.S. Supreme Court ruled in "Shelby County v. Holder" that Congress had exceeded its Fifteenth Amendment enforcement authority when it reauthorized a part of the Voting Rights Act (a coverage formula) that forced places with a history of discrimination to get federal approval before making changes to their election laws. This preclearance complemented and backstopped the more traditional way of enforcing civil rights, a federal lawsuit, and stopped states from enacting discriminatory changes to their voting laws before they could act. In striking the coverage formula, the Court effectively stripped traditional preclearance from the Voting Rights Act. From this perspective, the Court's ruling wrote out an essential tool for federal enforcement of voting rights, the crown jewel of the civil rights movement. At the same time, the Court validated an important new principle, the principle of equal state sovereignty, and defined a critical limit on congressional authority under the Fifteenth Amendment. In other words, the Court drew an important line between states rights and federal authority in enforcing civil rights. From this perspective, the Court protected states from an overreaching federal government in an area of traditional state responsibility, the states' election laws. This article explains the significance "Shelby County v. Holder" by defining how Congress designed the various provisions of the Voting Rights Act, and why.