What is gerrymandering?

Gerrymandering is the manipulation of electoral district boundaries to advantage a particular party, incumbent, or group. It works through two complementary techniques. Packing concentrates opposition voters into a small number of districts they win by huge margins, wasting their surplus votes. Cracking splits opposition voters across many districts so they fall just short in each. Applied together across a state, these can produce legislative delegations that diverge sharply from the statewide vote share, letting a party win a minority of votes and a majority of seats.

The name comes from an 1812 Massachusetts map signed by Governor Elbridge Gerry containing a district so contorted a newspaper cartoonist drew it as a salamander, producing the portmanteau. Districts are redrawn after each decennial census, and in most states the legislature controls the process, which creates the obvious conflict of politicians selecting their voters. Some states have shifted to independent or bipartisan commissions to reduce that conflict, with mixed results. The legal landscape is split: racial gerrymandering can be challenged under the Constitution and the Voting Rights Act, but the Supreme Court held in 2019 that partisan gerrymandering claims are political questions beyond federal court review, leaving those challenges to state courts and state constitutions, which is why recent high-profile map litigation has largely played out at the state level.