Gerrymandering & Redistricting
How drawing district lines can predetermine election outcomes, and the ongoing fight over fair maps.
Drawing Power
Gerrymandering is the deliberate manipulation of electoral district boundaries to advantage a political party, group, or incumbent. The term dates to 1812, when Massachusetts Governor Elbridge Gerry approved a district so contorted it resembled a salamander. The practice is as old as single-member districts themselves, but modern computing and detailed voter data have made it far more precise and effective.
There are two main techniques. 'Packing' concentrates the opposing party's voters into a few districts where they win by overwhelming margins, wasting their surplus votes. 'Cracking' spreads the opposing party's voters across many districts so they fall short of a majority in each one. Used together, these techniques can transform a 50-50 state into one where the gerrymandering party wins 70 percent of seats.