Tremendous transformation marks the last three decades of American politics, and nowhere has this change been as distinctive and penetrating as in the American South. After 120 consecutive years of minority status, the rapid ascendancy of Southern House Republicans in the 1990s has reshaped the contours of contemporary American politics: increasing party polarization, making a Republican House majority possible, and, most recently, contributing to the revival of Democratic fortunes in national congressional elections. Southern Republican ascendancy constitutes an exemplar of party system change, made possible by three sequential factors: increasing Republican identification, redistricting, and the emergence of viable Republican candidates. Relying on existing and original data sources, this text presents the most recent example of large-scale partisan change. Beyond serving as a primer for the study of political parties, campaigns and elections, and Southern politics, Republican Ascendancy in Southern U.S. House Elections provides an original theoretical argument and an expansive view of why political change in the South has such strong implications for national politics.