What principle means the people have ultimate power?

The principle that means the people have ultimate political power is popular sovereignty. The phrase combines popular, meaning of or relating to the people, with sovereignty, meaning supreme political authority. Together it asserts that no king, dictator, court, legislature, agency, or party holds power independent of the public; all governmental authority flows from those who are governed.

The principle was a Founding-era response to the European tradition of monarchical sovereignty, where supreme authority rested in a hereditary ruler. Influenced by John Locke's Second Treatise of Government in 1689, Jean-Jacques Rousseau's Social Contract in 1762, and English parliamentary practice, the American Founders rejected royal sovereignty entirely. Thomas Jefferson built popular sovereignty into the Declaration of Independence in 1776, declaring that governments derive their just powers from the consent of the governed. The Constitution's Preamble made the principle structural: We the People do ordain and establish this Constitution.

Popular sovereignty is implemented through elections, representative institutions, the amendment process, and the supremacy of the written Constitution itself. Members of the House have always been directly elected; the Seventeenth Amendment in 1913 extended direct election to senators. Presidents are chosen through electors selected by voters in each state. State officials and most local officials are elected. Constitutional amendments must be ratified by elected state legislatures or by state conventions. Officials swear oaths to the Constitution, which derives its authority from the people.

The principle has not always been fully realized in practice. Voting rights were originally restricted to free white male property owners in most states. The Fifteenth, Nineteenth, Twenty-Fourth, and Twenty-Sixth Amendments and the Voting Rights Act of 1965 progressively expanded the electorate to include Black Americans, women, citizens of all economic classes, and those 18 and older. Modern debates over voter ID, mail-in voting, redistricting, and campaign finance continue to wrestle with how to honor the principle in concrete electoral rules.

Popular sovereignty does not authorize unlimited majority action. The Constitution cabins what majorities may do through the Bill of Rights, the structural separation of powers, and judicial review. Sovereign power is constitutionally exercised, not arbitrary.