Two-party system
Third parties, meaning a party other than one of the two dominant parties, are possible in two-party systems, but they are often unlikely to exert much influence by gaining control of legislatures or by winning elections. While there are occasional opinions in the media expressed about the possibility of third parties emerging in the United States, for example, political insiders such as the 1980 presidential candidate John Anderson think the chances of one appearing in the early twenty-first century is remote. A report in "The Guardian" suggested that American politics has been "stuck in a two-way fight between Republicans and Democrats" since the Civil War, and that third-party runs had little meaningful success.
Libertarian Party (United States)
While it is the third largest political party in the United States, it currently has no members in Congress or governorships, though it does hold three lower house state legislative seats. There are 511,277 voters (0.46% of total) registered as Libertarian in the 30 states that report Libertarian registration statistics and Washington, D.C. The Libertarian Party was the party under which the first electoral vote was cast for a woman (Tonie Nathan) for Vice President in the 1972 United States presidential election due to a faithless elector.