The upper South - starting in the Appalachian Mountains and stretching west across the Ohio and Tennessee River Valleys and into Arkansas - has its own culture and history distinct from the Deep South. It also has its own distinct political realignment that has pushed the region toward the right starting in the mid-1990s.

The region is defined by concentrations of unhyphenated Americans - whites who trace their ethnicity not to the European country of their ancestors, but directly to the United States. Examining counties with concentrations of these American ethnic identifiers, the book uses election data to show the region's rapid shift to the Republicans. Public opinion data shows the region was pushed to the Republicans by its conservatism on issues such as abortion, guns, and the environment, and the increased national salience of racial issues prompted by the emergence of Barack Obama and Donald Trump.