Political realignment

A political realignment, often called a critical election, critical realignment, or realigning election, in the academic fields of political science and political history, is a set of sharp changes in party ideology, issues, party leaders, regional and demographic bases of power of political parties, and the structure or rules of the political system, such as voter eligibility or financing. The changes result in a new political power structure that lasts for decades, replacing an older dominant coalition. Scholars frequently invoke the concept in American elections and occasionally those of other countries. American examples include the 1896 United States presidential election, when the issues of the American Civil War political system were replaced with those of the Populist and Progressive Era, and the 1932 United States presidential election, when the Populist and Progressive Eras were replaced by the New Deal-era issues of New Deal liberalism and modern conservatism. Realigning elections typically separate (what are known in the field of comparative politics as) party systems—with 1828, for example, separating the First Party System and the Second Party System in the US. It is generally accepted that the United States has had five distinct party systems, each featuring two major parties attracting a consistent political coalition and following a consistent party ideology, separated by four realignments. Political realignments can be sudden (1–4 years) or can take place more gradually (5–20 years). Most often, however, particularly in V. O. Key Jr.'s (1955) original hypothesis, it is a single "critical election" that marks a realignment. By contrast, a gradual process is called a secular realignment. Political scientists and historians often disagree about which elections are realignments and what defines a realignment, and even whether realignments occur. The terms themselves are somewhat arbitrary, however, and usage among political scientists and historians does vary.