Political parties are the basis of the American political system. Curiously, the Constitution makes no provisions for political parties nor for their role as the vehicle by which candidates for public office are proposed to the voters.
At the national level, the United States employs a two-party system that has remained remarkably durable throughout the nation's history, even though rival national parties have appeared and disappeared from the political scene. The Federalists, for example, who rallied around President George Washington, disappeared slowly after 1800; and the Whig Party, which arose in the 1830s in opposition to President Andrew Jackson, a Democrat, collapsed two decades later. Today, the Democratic Party, which traces its origins back to the nation's third president, Thomas Jefferson, and the Republican Party, founded in 1854, continue to dominate politics at the federal, state and local levels.
One explanation for the longevity of the Republican and Democratic parties is that they are not tight ideological organizations, but loose alliances of state and local parties that unite every four years for the presidential election. Both parties compete for the same broad center of the American electorate, and although Republicans are generally more conservative than Democrats, both parties contain relatively liberal and conservative wings that continually vie for influence.
Nevertheless, other parties are also active, and particularly at the state and local levels, they may succeed in electing candidates to office and in exercising considerable influence. During the early 20th century, for example, members of the Socialist Party were elected to the House of Representatives and as the mayors of over 50 towns and cities. The Progressive Party held the governorship of Wisconsin for a number of years and in 1974 an independent candidate became governor of Maine.