The Failure of Partisan Gerrymandering Metrics to Consider Race & Voting Rights

• In Event: Representation in the United States Congress

Abstract

Political scientists and mathematicians have created a number of clever metrics to detect the presence of partisan gerrymandering in legislative district maps. These measures include the efficiency gap, mean-median, extreme outcomes, GEO metric, and other measures of partisan gerrymandering. All of these measures fail to incorporate race and the voting rights protections for voters of color. This paper presents a critique of the extant measures for failing to incorporate communities of interest by race; and protection of minority voting rights. I also present alternative measures that incorporate race and fairness as well as partisan metrics. I show that some alleged redistricting maps using partisan-only metrics that are fair are in fact biased against voters of color; and that some redistricting maps that score poorly on partisan metrics in fact are fair for race and voting rights reasons. I use maps newly passed in 2022 to measure and motivate these critiques and new measures.

Author

• Christian R. Grose, University of Southern California