In recent years, a growing number of citizens have defected from the major parties to third party presidential candidates. During the elections in the past two decades, minor parties like those led by George Wallace and John Anderson, as well as independent efforts such as Ross Perot"s 1992 presidential campaign, have attracted more support than at any time since the 1920s. Third Parties in America explains why and when the two-party system deteriorates and third parties flourish. Relying on data from presidential elections between 1840 and 1992, it identifies the situations in which Americans abandon the major parties and shows how third parties encourage major party responsiveness and broader representation of political interests.