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 Progressi