An American political party is a political organization that seeks to influence government policy through its own nominated candidates. Parties often have an ideology or specific goal set when trying to seat their candidate in a political office. The United States has more than 50 national political parties, not including regional political parties, yet Congress -- as of time of publication -- is composed of Democrats, Republicans and two Independent senators, Joe Lieberman of Connecticut and Bernie Sanders of Vermont.
The United States was not established as having a two-party system. Neither party is mentioned in the Constitution. In the country's infancy, two different parties were trying to seize control of the government: the Democratic-Republicans and the Federalists. Over the years, Whigs replaced the Federalists, and the Whigs collapsed just before the Civil War. After that, the Democratic-Republican party split into Democrats and Republicans.
Many theories exist as to why only two main political parties control the United States, but two reasons are that it takes plenty of votes and dollars to win an election, and Americans are used to the stability of a two-party system. It is difficult for a third party to take votes from Democrats and Republicans: The two major parties have more money invested in campaigning via informal institutional support, including media coverage, voter loyalty and public perception. Third parties such as the Constitution Party, the Green Party and the Libertarian Party -- in all of American history -- have never elected a president because of these circumstances, although two presidents, George Washington and Andrew Johnson, had no political affiliation while in office.
Various circumstance make it harder for a third party to equally compete for office, including donation limits, disclosure laws, campaign subsidies and ballot registration restrictions. Federal campaign laws limit the size of donation an individual can make directly to a federal campaign to $1,000 prior to the party's nomination. Disclosure laws allow all campaign donations to be reported; thus, major donors risk the chance of being cast into the public eye if they choose to finance a person who challenges the two-party system. Congress awards tax dollars to the Democrats and Republicans via campaign subsidies. For the 2000 general election, George W. Bush and Al Gore each spent $67.6 million from the U.S. Treasury on the campaign; meanwhile, third parties had to raise money $1,000 at a time. State laws also make it difficult and expensive for third-party candidates to get on the ballot. In some states, third-party candidates need more petition signatures and have to pay higher filing fees than the Democratic and Republican candidates.