Draw the Lines Can you rig an election with a map?

Glossary

Electoral district

An area whose voters elect one representative. Every U.S. state is divided into House districts with roughly equal populations, with each state required to have at least one member in the House of Representatives.

Redistricting

Redrawing district boundaries inside a state so each district has about the same number of people. It happens after every 10-year census, once seats have been reapportioned (re-divided) among the states.

Gerrymandering

Drawing district lines to give one party or group an advantage.

Packing

Cramming the other side's voters into one district they win by a landslide, so their extra votes are wasted.

Cracking

Splitting the other side's voters across several districts so they lose all of them narrowly.

Shape score

How tidy a district's shape is (the Polsby–Popper score). 1.0 is a perfect circle; near 0 is stringy or spread out. Depending on geographic features, the shape of a district provides a clue to whether it has been manipulated to favor one party or another.