Redistricting Glossary
and Key Terms

Apportionment: The determination of the proportional number of members each US state sends to the House of Representatives, based on population figures.

Census: The counting and survey of every person in a population. In the U.S., a census is taken every 10 years.

Census Bureau: The federal government agency that administers the census. 

Coalition District: A district in which combined racial minorities make up a majority of the population and where the voters from these different racial groups vote together to elect the minority-preferred candidate. Coalition districts are not legally required by the Voting Rights Act 

Communities of Interest: Groups with a significant shared interest should be kept together in order to boost their voice in government. Can be defined differently according to different state statutes, case law, and post-facto by governments. EX: Courts have affirmed that socio-economic status, education level, religion, and health factors can define a community that would be relevant to redistricting.

Compact: Districts should be reasonably shaped. Example below:

Contiguous: Each district should be a single connected component. Only required by 30-some states by law. Mostly straightforward except for when you’re building from disconnected units, or water crossings to consider.

Cracking: A splitting of racial minority communities into two+ districts so that the minority community is not a significant portion of any district. 

Equal population: Districts within a polity should all have very close to the same population. The standard way to count is to use the Decennial Census numbers. This applies to all 50 states, and Congressional districts are usually balanced to one-person deviation across a state.

Equal Proportions Method: The official method used by the U.S. Census Bureau to determine how many seats each state is assigned to the U.S. Congress according to the decennial Census

Gerrymandering: The process of redrawing district lines to increase unduly a group’s political power. This is a conscious attempt to draw district lines specifically to increase the likelihood of a particular political result.

GIS (Geographic Information System): Computer software used to create redistricting maps.

Incumbency: In some states, there’s a rule that implies that new maps should avoid pairing incumbents to run against each other. (AKA ‘double bunking’). 

Incumbent protection gerrymandering aka ‘bipartisan’ or ‘sweetheart’ gerrymandering: Those drawing the lines try to ensure that each party holds on to the districts it already controls, effectively divvying up the state to preserve the partisan status quo.

Influence District: A district where a racial or ethnic minority group doesn’t make up a majority of voters but does have enough members of the minority group to influence an election substantially/ the decisions of an elected representative

Malapportionment: Assigning unequal numbers of people to districts, and making some votes worth less than others - instead of redrawing the district lines

Nesting: 8 states currently require that the state House districts nest inside the state Senate districts two-to-one, and two additional states require three-to-one nesting.             

Partisan gerrymandering: The political party in control of the line-drawing process draws districts to favor itself and limits opportunities for the opposition party. (R’s in GA)

Partisan properties: A few states have rules indicating that there is a priority on the creation of competitive districts or districts that react responsively to changes in voter opinion, and numerous states have considered adopting language of that kind. Several other states forbid considering partisan data in the redistricting process. 

Political boundaries: Counties, cities, and other relevant municipalities should not be split among multiple districts when there is a way to keep them whole.

Reapportionment: The process every 10 years of deciding, based on population, how many representatives a state will receive. Example from 2012 below:

Redistricting: The process by which new congressional and state legislative district boundaries are drawn. Each of Georgia's 14 United States Representatives and 236 state legislators are elected from political divisions called districts. United States Senators are not elected by districts, but by the states at large. District lines are redrawn every 10 years following completion of the United States census. The federal government stipulates that districts must have nearly equal populations and must not discriminate on the basis of race or ethnicity

Units: some states prescribe which building-block pieces plans should be assembled from. EX: Louisiana makes it hard to change the precincts, and requires plans to be built from whole precincts. Iowa requires that counties be kept whole. Massachusetts keeps precincts whole in their legislative plans.

Voting Rights Act: Districts must not undercut the opportunity for minority communities to elect candidates of choice. This is a federal law on the books since 1965.