|Part of the Politics series|
Redistricting is the process of drawing electoral district boundaries in the United States. A congressional act passed in 1967 requires that representatives be elected from single-member districts, except when a state has a single representative, in which case one state-wide at-large election be held.
Seven states have only a single representative in the United States House of Representatives for the entire state, because of their low populations. These are Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont, and Wyoming. These states do not need redistricting for the House and elect members on a state-wide at-large basis.
In 25 states, the state legislature has primary responsibility for creating a redistricting plan, in many cases subject to approval by the state governor. To reduce the role that legislative politics might play, thirteen states (Alaska[a], Arizona, California, Colorado, Hawaii, Idaho, Michigan, Missouri, Montana[b], New Jersey, Ohio, Pennsylvania, and Washington) determine congressional redistricting by an independent or bipartisan redistricting commission. Five states: Maine, New York, Rhode Island, Vermont[c], and Virginia give independent bodies authority to propose redistricting plans, but preserve the role of legislatures to approve them. Arkansas has a commission composed of its governor, attorney general, and secretary of state.
By law, the 43 states with more than one Representative must redistrict after each decennial census to account for population shifts within the state as well as (when necessary) to add or remove congressional districts. States are not prevented from redistricting at any time between censuses up to and including redistricting prior to each congressional election, provided such redistricting conforms to various federal laws. However, "mid-decade" redistricting proposals (such as what occurred in 2003 in Texas) have typically been highly controversial.
State constitutions and laws also mandate which body has responsibility over drawing the state legislature boundaries. In addition, those municipal governments that are elected on a district basis (as opposed to at-large) also redistrict.
The Reapportionment Act of 1929 withdrew the size and population requirements for Congressional districts, last stated in the Apportionment Act of 1911. The previous apportionment acts required districts be contiguous, compact, and equally populated.
Each state can set its own standards for Congressional and legislative districts. In addition to equalizing the population of districts and complying with federal requirements, criteria may include attempting to create compact, contiguous districts, trying to keep political units and communities within a single district, and avoiding the drawing of boundaries for purposes of partisan advantage or incumbent protection.
Redistricting may follow other criteria depending on State and local laws:
- equal population
- preservation of existing political communities
- partisan fairness
- racial fairness
Esri has offered its services as a platform for redistricting to allow for complete government transparency. Since the process of redistricting is intrinsically linked to geography, GIS can address this issue effectively. However, Maptitude is the most widely used GIS software for redistricting, and has also been effectively used to democratize the process.
Gerrymandering, the practice of drawing district boundaries to achieve political advantage for legislators, involves the manipulation of district boundaries to leave out, or include, specific populations in a particular district to ensure a legislator's reelection or to advantage their party.
In states where the legislature (or another body where a partisan majority is possible) is in charge of redistricting, the possibility of gerrymandering (the deliberate manipulation of political boundaries for electoral advantage, usually of incumbents or a specific political party) often makes the process very politically contentious, especially when the majorities of the two houses of the legislature, or the legislature and the governor, are from different parties.
Partisan domination of state legislatures and improved technology to design contiguous districts that pack opponents into as few districts as possible have led to district maps which are skewed towards one party. Consequently, many states including Florida, Georgia, Maryland, Michigan, North Carolina, Ohio, Pennsylvania, Texas and Wisconsin have succeeded in reducing or effectively eliminating competition for most House seats in those states. Some states, including New Jersey and New York, protect incumbents of both parties, reducing the number of competitive districts.
The state and federal court systems are often involved in resolving disputes over Congressional and legislative redistricting when gridlock prevents redistricting in a timely manner. In addition, those disadvantaged by a proposed redistricting plan may challenge it in state and federal courts. Justice Department approval (which is known as pre-clearance) was formerly required under Section 5 of the Voting Rights Act of 1965 in certain states that have had a history of racial barriers to voting. The Supreme Court's ruling on the Pennsylvania redistricting effectively allows elected officials to select their constituents by eliminating most of the grounds for constituents to challenge district lines.
U.S. Supreme Court cases relating to redistricting
- Baker v. Carr
- Gray v. Sanders
- Wesberry v. Sanders
- Burns v. Richardson
- Reynolds v. Sims
- Gaffney v. Cummings
- Karcher v. Daggett
- Thornburg v. Gingles
- Davis v. Bandemer
- Growe v. Emison
- Voinovich v. Quilter
- Shaw v. Reno
- Johnson v. DeGrandy
- Miller v. Johnson
- Bush v. Vera
- Hunt v. Cromartie
- Vieth v. Jubelirer
- League of United Latin American Citizens v. Perry
- Bartlett v. Strickland
- Gill v. Whitford
- Benisek v. Lamone
- Rucho v. Common Cause
- Since Alaska only has a single Representative, its congressional redistricting laws are not currently in force.
- Since Montana only has a single Representative, its congressional redistricting laws are not currently in force.
- Since Vermont only has a single Representative, its congressional redistricting laws are not currently in force.
- 2 U.S. Code § 2c - Number of Congressional Districts; number of Representatives from each District
- "2009 Redistricting Commission Table". National Conference of State Legislatures (NCSL). June 28, 2008. Retrieved 2013-09-06.
- Blake, Aaron. "Government Redistricting Web Sites". Purdue University Libraries. Retrieved 2009-08-25.
- "TheHill.com - Redistricting looms over 2010 landscape". thehill.com. Retrieved 2009-08-25.
- Miller, Jason C.,Community as a Redistricting Principle: Consulting Media Markets in Drawing District Lines (July 6, 2010). Indiana Law Journal Supplement, Vol. 5, 2010.
- "ArcGIS is Making Redistricting More Efficient and Transparent" (PDF), ArcUser, p. 26, Spring 2018
- Jacobson, Gary (2013). The Politics of Congressional Elections. New Jersey: PEARSON Education. p. 9.
- Supreme Court to Consider the Politics of Redistricting
- Redistricting tools infodump
- Creating Transparency, Openness, and Trust: Modern Approaches to Redistricting
- Public will get to propose 6th Congressional District lines to commission online
- "Vieth v. Jubelirer". supct.law.cornell.edu. Retrieved 2009-08-25.
- All About Redistricting Includes state criteria.
- Creating Fair Congressional Districts A site with an algorithm using just population and state shape for creating congressional districts.
- redistrictinginamerica.org A comprehensive source for information about redistricting in all fifty states from the Rose Institute of State and Local Government
- MappingSoftware.com Maptitude for Redistricting News
- Congressional Apportionment from the Office of the Clerk at the United States House of Representatives, including historical representation by state
- District sizes and other data from 1900-2000 from the United States Census
- Government Redistricting Web Sites from GovDocs at Purdue University Libraries, includes list of state websites
- Public Mapping Project
- A Citizen's Guide to Redistricting, 2010 Edition, downloadable
- Reapportionment and Redistricting in the U.S. from the ACE Project
- Rodriguez, Lori. "Getting point of redistricting." Houston Chronicle. Saturday August 24, 1991. A25.
- Jeffrey B. Lewis; et al. (2013). "Digital Boundary Definitions of United States Congressional Districts, 1789-2012". University of California, Los Angeles.
- "Redistricting: How Powerful Interests Are Drawing You Out of a Vote". ProPublica.
- The Redistricting Game - Where Do You Draw the Lines A simulation of how redistricting works. It uses the real US laws and practices and incorporates quotes from US political leaders.