Gerrymandering

Gerrymandering is the manipulation of district boundaries to favor a party, incumbent or group. The name comes from an 1812 Massachusetts district shaped like a salamander, approved under Governor Elbridge Gerry.

The main techniques are "packing," concentrating the opposing party's voters into a few districts to win others by narrower margins, and "cracking," splitting them across many districts so they cannot form a majority. Modern mapping software and detailed voter data have made it more precise. Both parties have engaged in it where they control redistricting, and independent commissions are one alternative.

The courts treat two kinds differently. In Rucho v. Common Cause (2019), the Supreme Court held that partisan gerrymandering claims are non-justiciable in federal court, a political question doctrine holding, though state courts and constitutions may provide remedies. Racial gerrymandering claims remain reviewable under the Equal Protection Clause and the Voting Rights Act. Critics of the practice, on both sides, say it lets politicians pick their voters and reduces competition; defenders argue some political considerations are unavoidable in drawing lines and that geography also shapes outcomes.