The United States has a two-party system. The existence of only two dominant parties stems largely from election rules that provide for single-member districts
and winner-take-all elections.
Each "district" can have only one winner in any election, the person who receives the most votes. So no matter how popular a third party, it will not win a single seat in any legislature until it becomes powerful enough in a single district to take an election. By contrast, many democracies have proportional representation,
in which officials are elected based on the percentage of votes their parties receive, and more than two dominant parties. If a party wins 10 percent of the vote in an election where 100 seats are at stake, it gets to have 10 of the seats. In a multiparty system, parties may form a coalition,
an alliance between parties, to pool their votes if there is agreement on a major issue. Proportional representation encourages the formation of parties that are based on narrowly defined interests.
The Electoral College is also a factor in sustaining the two-party system. Even if the popular vote in a state is very close, the winner gets all of the state's electoral votes. This arrangement makes it extremely difficult for a third party to win. In the 1992 presidential election, Ross Perot captured almost 20 percent of the popular vote across the country but did not receive a single electoral vote.
The Federalists and the Democratic Republicans
Although the Constitution does not provide for political parties, two factions quickly emerged. One group, led by John Adams and Alexander Hamilton, favored business development, a strong national government, and a loose interpretation of the Constitution. The followers of Thomas Jefferson, known as Democratic Republicans, called for a society based on small farms, a relatively weak central government, and a strict interpretation of the Constitution.
The election of 1800 had constitutional implications. The Democratic Republicans chose Jefferson for president and Aaron Burr for vice president. The party's electors split their ballots for both men, resulting in a tie that was resolved in the House of Representatives. The Twelfth Amendment (1804), which required electors to vote separately for president and vice president, recognized that political parties would nominate one candidate for each office.
Jacksonian Democrats and the Whigs
During the 1820s, with the country expanding and many states dropping their property qualifications for voting, the size of the electorate grew. Andrew Jackson took advantage of this change, and from his election in 1828, the Democrats represented an alliance of small farmers, Westerners, and "mechanics," the term used for the working class. The Whig Party (1834) supported business, a national bank, and a strong central government. When the Whigs broke up in the 1850s, they were replaced by the Republican Party.
This period saw important changes in how political parties operate. In the presidential election of 1832, candidates were chosen through a national convention of representatives from the states' parties, and a party platform, a statement of the party's beliefs and goals, was issued.
Democrats and Republicans
The Civil War split the political parties in several ways. The Republican party's strength lay in the North; Abraham Lincoln did not receive a single electoral vote from a Southern state in 1860. The Democrats in the North divided into War Democrats, who supported the war effort but claimed the Republicans were doing a poor job of leading the Union, and the Peace Democrats, or Copperheads, who opposed the war and were suspected of disloyalty to the Union. To win the election of 1864, the Republicans reorganized themselves as the Union party to attract votes from the War Democrats and nominated War Democrat Andrew Johnson for vice president. When Lincoln was assassinated, Democrat Johnson became president.
Following the Civil War, Republicans moved quickly to consolidate their control of the United States government. They quickly added a series of Western states to the Union, states that they expected would remain firm in their support for Republicans. They also set up (often corrupt) governments in the South that would regulate state elections in a manner beneficial to the party. Their record was mixed. The Democrats and Republicans alternated control of Congress, but only two Democratic presidents — Grover Cleveland (1884–1888, 1892–1896) and Woodrow Wilson (1912–1920) — were elected up to 1932. The Republican party's pro-business positions played well in the industrial North and Midwest, while the Democrats held the "solid South." The large number of immigrants who came to the United States, together with the growing industrial workforce, laid the basis for strong, largely Democratic political machines in New York, Chicago, and other large cities.
The New Deal coalition and Republican resurgence
The Great Depression brought about a major shift in political party allegiance. African-American voters, who had traditionally supported the Republicans since Reconstruction, now joined the unemployed, the immigrants and their descendants, the liberal intellectuals, and the South in backing Franklin Roosevelt. The Democratic party's New Deal coalition redefined the role of the federal government as an active agent in promoting the general welfare. The Democrats dominated national politics for the next 20 years. Roosevelt's New Deal was followed by Harry Truman's Fair Deal; Republican Dwight Eisenhower (1952–1960) found it impossible to dismantle the New Deal agencies that had become an integral part of American society.
Democratic dominance collapsed in the 1960s. Young radicals turned away from liberalism in response to the Vietnam War, while moderate Democrats increasingly blamed their party for the rise of lawlessness that had accompanied liberal social change during the decade — especially the explosion of urban rioting that devastated American cities starting in 1964. From the 1968 election of Richard Nixon to Bill Clinton's 1992 victory, only one Democrat attained the White House: Jimmy Carter, whose term spanned 1976 to 1980. This succession of Republicans was due in part to the party's Southern strategy, which began to bring Southern states into the Republican column in presidential elections. Not until 1994 were Republicans able to consolidate their power by capturing control of Congress, the first time they had held both the House and the Senate in almost half a century. The Republicans continued to dominate Congress, albeit often with slim majorities, until 2006; opposition to the war in Iraq and Bush's declining popularity returned the Democrats to power in the midterm elections.