The Purpling of the Peach: Demographic Change and Partisanship in the State of Georgia

This dissertation estimates voting behavior by race and ethnicity in Georgia's 2020 presidential election, one of two long-time Republican states 'flipped' by Democratic candidate Joe Biden. The purpose is to evaluate media claims that demographic change and minority voter mobilization clinched the victory. Developing empirical evidence elevates public discourse by challenging the public misconception that the political dividends of race/ethnic diversity flow uniquely to the Democratic party. Parties, in turn, can be more responsive to their constituencies. State-level research can guide policies on election security, redistricting, and minority rights. Two methodological approaches are implemented that have not previously been directly compared. The first is the aggregation technique of ecological inference, which is the current standard used for Voting Rights Act litigation concerning racially polarized voting. The second is the disaggregation technique of multilevel regression and poststratification, an increasingly popular approach for producing statistical estimates for sociodemographic subgroups at lower-level geographies. The findings challenge the conventional wisdom that a combination of increased race/ethnic diversity and grassroots voter mobilization activity secured Democratic candidate Joe Biden's electoral triumph. The empirical evidence supports the hypothesis that the defection of majority White voters to the Democratic party tipped Georgia's partisan balance. In addition, White voters with post-secondary educational attainment of a four-year degree or greater displayed the largest shift. The results align with previous research on the secular realignment of college-educated White voters with the Democratic party. Future research directions are discussed in the context of the role political demography could play in promoting high-quality information related to race/ethnic change in the electorate.