Electoral district

An electoral district is a geographic area whose voters elect one or more representatives to a legislative or other elected body. District boundaries determine which voters participate in each contest and how votes translate into representation.

Apportionment: The allocation of legislative seats among geographic units or populations. Apportionment determines how many representatives each district or region receives.
Gerrymandering: The manipulation of electoral boundaries to advantage a political party or group. Drawing districts strategically can produce outcomes that persist even when votes shift.
At-large election: An election in which representatives are chosen by voters across an entire jurisdiction rather than separate districts. It selects representatives across a shared electorate instead of separate geographic constituencies.
Baker v. Carr: A 1962 United States Supreme Court case that made legislative apportionment claims justiciable in federal court. The case opened federal courts to challenges over unequal district populations.
Redistricting: The process of revising electoral district boundaries. Redistricting changes which voters are grouped together in each district.
Malapportionment: Unequal representation caused by districts containing substantially different numbers of people. Unequal district populations give some voters more influence over representation than others.
Proportional representation by party list: A proportional system in which voters choose party lists and seats are allocated according to vote share. Party-list systems can allocate seats without assigning each representative to a single-member district.
Reynolds v. Sims: A 1964 United States Supreme Court case requiring state legislative districts to have roughly equal populations. Its one-person, one-vote rule constrained how unevenly state districts could be populated.
Single-member district: An electoral district that elects one representative. This common district form awards each constituency a single seat.
Packing and cracking: Boundary-drawing tactics that concentrate or divide opposing voters to weaken their electoral influence. These techniques show how district lines can alter the distribution of political power.

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