Redistricting and Gerrymandering: Legal Framework and Recent Developments

Redistricting is the process of redrawing legislative district boundaries following each decennial census to reflect population changes and ensure equal representation. Article I, Section 2 of the Constitution requires apportionment of House seats among the states based on population, and the Supreme Court's one-person, one-vote decisions (Wesberry v. Sanders, Reynolds v. Sims) require that districts within each state have substantially equal populations. Beyond the equal population requirement, states have significant discretion in how they draw districts, subject to the Voting Rights Act and other legal constraints.

Gerrymandering—the manipulation of district boundaries for political advantage—has a long history in American politics, dating to the early 19th century. Modern gerrymandering is facilitated by sophisticated mapping software and granular demographic and voting data, enabling map-drawers to predict with increasing accuracy how different configurations will affect electoral outcomes. Both racial gerrymandering (drawing districts to dilute or pack minority voters) and partisan gerrymandering (drawing districts to advantage one political party) are subjects of ongoing legal and policy debate.

The Fourteenth Amendment's Equal Protection Clause requires that legislative districts have substantially equal population and prohibits the predominant use of race in drawing district lines (Shaw v. Reno, 1993; Miller v. Johnson, 1995). Section 2 of the Voting Rights Act prohibits voting practices that deny or abridge the right to vote on account of race, including redistricting plans that dilute minority voting strength. Under the Gingles framework (Thornburg v. Gingles, 1986), plaintiffs must demonstrate that a minority group is sufficiently large and geographically compact to constitute a majority in a single-member district, that the minority group is politically cohesive, and that bloc voting by the majority usually defeats the minority group's preferred candidates.

Following Shelby County v. Holder (2013), which effectively invalidated Section 5's preclearance formula, covered jurisdictions are no longer required to obtain federal approval before implementing redistricting plans. This has shifted redistricting oversight from a proactive review process to reactive litigation under Section 2, placing the burden of proof on challengers and allowing potentially discriminatory maps to be used in elections during the pendency of litigation.

Congressional options include enacting federal redistricting standards that would establish criteria for congressional map-drawing, such as requirements for compact and contiguous districts, preservation of communities of interest, and limitations on partisan data use. Proposals to require independent redistricting commissions for congressional districts have been advanced in comprehensive voting rights bills, though they raise questions about Congress's authority under the Elections Clause.

Other options include restoring and updating the VRA's preclearance regime through new coverage formulas, establishing enhanced transparency requirements for the redistricting process, creating federal standards for redistricting data and public participation, and addressing the impact of prison gerrymandering by requiring incarcerated individuals to be counted at their pre-incarceration addresses for redistricting purposes.

The 2020 redistricting cycle produced extensive litigation in state and federal courts, with several states' maps being redrawn by courts or commissions. The Supreme Court's decision in Moore v. Harper (2023) rejected the independent state legislature theory, affirming that state courts may review congressional redistricting plans under state constitutional provisions. Ongoing litigation continues to shape the redistricting landscape as states prepare for the 2030 Census and the next round of redistricting. Congressional interest in federal redistricting standards persists, though enactment of comprehensive reform faces significant political obstacles.