Redistricting and Gerrymandering: How District Maps Shape Elections

Every ten years, following the U.S. Census, congressional and state legislative districts are redrawn to reflect population changes. This redistricting process has enormous consequences for electoral outcomes — and it has become one of the most hotly contested areas of election law.

The Gerrymandering Problem

Gerrymandering — drawing district lines to benefit a particular party or group — is as old as American politics. The term itself derives from a 19th-century Massachusetts governor who approved a salamander-shaped district designed to benefit his party. Modern technology has made partisan gerrymandering far more precise and effective: sophisticated mapping software allows mapmakers to draw districts that reliably produce partisan outcomes even in competitive states.

Legal Standards

The legal landscape for challenging gerrymandering is complex. The Supreme Court ruled in Rucho v. Common Cause (2019) that federal courts cannot adjudicate partisan gerrymandering claims — the Court held that determining when partisanship has gone too far is a political question beyond judicial reach. This leaves partisan gerrymandering challenges primarily to state courts applying state constitutional standards, and to independent redistricting commissions in states that have established them.

Racial Gerrymandering

Racial gerrymandering — using race as the predominant factor in drawing district lines — remains subject to federal judicial review under the Equal Protection Clause and the Voting Rights Act. The Supreme Court's 2023 decision in Allen v. Milligan reaffirmed that Section 2 of the VRA requires states to create majority-minority districts in some circumstances, setting up continued litigation over how race and partisanship interact in the redistricting process.