Argued April 20, 1993.Decided June 28, 1993.

Justices Guy-Uriel CHARLES and Luis FUENTES-ROHWER delivered the opinion of the Court.

What lessons can we draw from the study of 2011 state legislative redistricting? We find that, on the one hand, predicting partisan gerrymandering is relatively simple: gerrymandering occurs when one party can monopolize redistricting and has an incentive to draw biased maps. One the other hand, our investigations of racial segregation and political geography reveal the intimate links between racial gerrymandering and political gerrymandering and suggest that the Republican Party in 2011 was willing to use racial vote dilution in many states in order to achieve extreme bias. We conclude with an assessment of redistricting reforms in Virginia and “best practices” in preventing partisan gerrymandering.

We investigate the impact of Voting Rights Act reforms that have required states to draw “majority-minority” districts and to abandon the use of multimember state legislative districts. Have these changes led to more bias in districting, as is often claimed? Our findings show that Republican bias is not an unavoidable outcome of minority districting. When Republicans are in charge, we often find more bias in states with large and geographically segregated Black and Latinx populations. In this regard, Republican gerrymanderers appear to use majority-minority districting as a tool for creating partisan advantage. But we do not see the same outcomes when Democrats, both parties, or independent actors are in charge. We also find that among the handful of states that still use multimember districts to elect state legislators, the average district magnitude in a state legislature imposes a ceiling on the level of bias achievable. However, when partisans are not in charge, multimember districts do not appear to limit partisan bias. Once again, the key variable in predicting the occurrence of bias in districting is whether or not one party controlled redistricting.

Although scholars have investigated the effects of redistricting for many decades, surprisingly little is known about the causes of redistricting outcomes. We argue that studying state legislative redistricting in 2011 provides a unique opportunity to identify the theoretical determinants of partisan gerrymandering and assess the political, social, and democratic consequences of bias. We also argue that the story of 2011 redistricting is incomplete without a comprehensive investigation of the causes and consequences of redistricting of state legislatures. Ultimately, our findings reveal the interconnectedness of racial and political gerrymandering and suggest that partisan bias has long-term consequences for public policy and democratic health, yet they also show that it is possible to design redistricting institutions to prevent bias.

Since the 1960s, the judiciary has become a key player in redistricting, and litigation has become an increasingly common feature of the decennial redistricting process. How do the courts fare when they draw the lines? We investigate the effects of court intervention in several states where federal and state courts redrew or forced changes to state legislative maps. We find that courts are only a partial solution to the problem of gerrymandering, because judicial actors are minimalistic in their treatment of redistricting and, as incrementalists, have a tendency to avoid extreme change. While the federal courts have been assertive in combatting racial gerrymandering, state courts have had only limited effect on partisan bias when they have been delegated the task of redistricting.

Shortly after the adoption of the Voting Rights Act of 1965, progressive reformers recognized new threats to minority representation that went beyond minority disenfranchisement and included efforts to dilute minority representation. Progressive justices aligned with the Democratic Party helped to refashion election law to address these evolving shortcomings by reinterpreting the statute as well as the Fourteenth and Fifteenth Amendments. Conservative justices countered by proposing new, restrictive doctrinal positions. But when those positions deviated from the wishes of elected Republicans, they capitulated and instead developed a new right discouraging racial gerrymandering. The pattern of evolving doctrinal positions is best described by the deliberative partnership thesis.