Redistricting in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
is the process of drawing
electoral district
An electoral (congressional, legislative, etc.) district, sometimes called a constituency, riding, or ward, is a geographical portion of a political unit, such as a country, state or province, city, or administrative region, created to provi ...
boundaries.
For the
United States House of Representatives
The United States House of Representatives is a chamber of the Bicameralism, bicameral United States Congress; it is the lower house, with the U.S. Senate being the upper house. Together, the House and Senate have the authority under Artic ...
, and state legislatures, redistricting occurs after each
ten-year census.
The
U.S. Constitution in Article 1, Section 2, Clause 3 provides for
proportional representation
Proportional representation (PR) refers to any electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions (Political party, political parties) amon ...
in the House of Representatives. The
Reapportionment Act of 1929 required that the number of seats in the U.S. House of Representatives be kept at a constant 435, and a 1941 act made the reapportionment among the states by population automatic after every decennial census. Reapportionment occurs at the federal level followed by redistricting at the state level. According to ,
Article I, Section 4 left to the legislature of each state the authority to establish congressional districts;
however, such decisions are subject to judicial review.
In most states redistricting is subject to political maneuvering, but some state legislatures have created independent commissions.
The
Uniform Congressional District Act (enacted in 1967) requires that representatives be elected from
single-member districts. When a
state has a single representative, that district will be state-wide.
Gerrymandering in the redistricting process has been a problem since the early days of the republic.
In recent years, critics have argued that redistricting has been used to neutralize minority voting power. Supporters say it enhances electoral competitiveness.
Legislative representatives
Federal

Six states have a single representative in the
United States House of Representatives
The United States House of Representatives is a chamber of the Bicameralism, bicameral United States Congress; it is the lower house, with the U.S. Senate being the upper house. Together, the House and Senate have the authority under Artic ...
, because of their low populations. These are
Alaska
Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...
,
Delaware
Delaware ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic and South Atlantic states, South Atlantic regions of the United States. It borders Maryland to its south and west, Pennsylvania to its north, New Jersey ...
,
North Dakota
North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...
,
South Dakota
South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...
,
Vermont
Vermont () is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, New Hampshire to the east, New York (state), New York to the west, and the Provinces and territories of Ca ...
, and
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
. These states do not need redistricting for the House and elect members on a state-wide
at-large
At large (''before a noun'': at-large) is a description for members of a governing body who are elected or appointed to represent a whole membership or population (notably a city, county, state, province, nation, club or association), rather tha ...
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
A governor is an politician, administrative leader and head of a polity or Region#Political regions, political region, in some cases, such as governor-general, governors-general, as the head of a state's official representative. Depending on the ...
.
To reduce the role that legislative politics might play, thirteen states (
Alaska
Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...
,
Arizona
Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...
,
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
,
Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
,
Hawaii
Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...
,
Idaho
Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...
,
Michigan
Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...
,
Missouri
Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...
,
Montana
Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...
,
New Jersey
New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
,
Ohio
Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
,
Pennsylvania
Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
, and
Washington) determine congressional redistricting by an independent or bipartisan
redistricting commission.
Five states:
Maine
Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...
,
New York,
Rhode Island
Rhode Island ( ) is a state in the New England region of the Northeastern United States. It borders Connecticut to its west; Massachusetts to its north and east; and the Atlantic Ocean to its south via Rhode Island Sound and Block Is ...
,
Vermont
Vermont () is a U.S. state, state in the New England region of the Northeastern United States. It borders Massachusetts to the south, New Hampshire to the east, New York (state), New York to the west, and the Provinces and territories of Ca ...
, and
Virginia
Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...
give independent bodies authority to propose redistricting plans, but preserve the role of legislatures to approve them.
Arkansas
Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...
has a commission composed of its governor, attorney general, and secretary of state.
By law, the forty-four 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.
Federal law (including the
Constitution
A constitution is the aggregate of fundamental principles or established precedents that constitute the legal basis of a polity, organization or other type of entity, and commonly determines how that entity is to be governed.
When these pri ...
) does not prevent states 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. Because of this, many states prohibit mid-decade redistricting, although this is more prevalent for state legislative redistricting than for congressional redistricting. Some also link it to a specific year or to the decennial census. It is unclear to what extent mid-decade redistricting would be legal in those states.


Apart from mid-decade redistricting initiated by state legislatures (as happened in
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
), both federal and state courts can also order the redistricting of certain maps between-censuses (because said maps were ruled unconstitutional or against federal law, for example). Examples of this are the redistricting that occurred between the 2016 and 2018 elections in
Pennsylvania
Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
or the redistricting that occurred in
North Carolina
North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...
.
State
State constitutions and laws also mandate which body has responsibility over drawing the state legislature boundaries. In addition, those
municipal government
A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate.
The term ''municipality'' may also mean the go ...
s that are elected on a district basis (as opposed to an
at-large
At large (''before a noun'': at-large) is a description for members of a governing body who are elected or appointed to represent a whole membership or population (notably a city, county, state, province, nation, club or association), rather tha ...
basis) also redistrict.
Redistricting criteria
The
Reapportionment Act of 1929 did not state any size and population requirements for congressional districts, last stated in the
Apportionment Act of 1911, since the 1911 Act was still in force. However, the Supreme Court ruled that the 1911 Act was no longer in force even though Congress never repealed it. 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:
# compactness
#
contiguity
# equal
population
Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and pl ...
# preservation of existing political communities
# partisan fairness
# racial fairness
Gerrymandering
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
incumbent
The incumbent is the current holder of an office or position. In an election, the incumbent is the person holding or acting in the position that is up for election, regardless of whether they are seeking re-election.
There may or may not be ...
s or a specific
political party
A political party is an organization that coordinates candidates to compete in a particular area's elections. It is common for the members of a party to hold similar ideas about politics, and parties may promote specific political ideology, ...
) 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
Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
,
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the South Caucasus
* Georgia (U.S. state), a state in the southeastern United States
Georgia may also refer to:
People and fictional characters
* Georgia (name), a list of pe ...
,
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
,
Michigan
Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...
,
North Carolina
North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...
,
Ohio
Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...
,
Pennsylvania
Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
,
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
and
Wisconsin
Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...
have succeeded in reducing or effectively eliminating competition for most House seats in those states. Some states, including
New Jersey
New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
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.
Other redistricting reforms
In addition to the establishments of
redistricting commissions in multiple states, proposals have been fielded to draft
interstate compacts between states on congressional redistricting. These have been proposed in the legislatures of
Maryland
Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...
and
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
since the 2010s in order to reduce redistricting-related litigation, prevent partisan "arms races" over reapportionment and partisan gerrymandering, and reduce perceptions of nonpartisan redistricting as unilateral disarmament.
To date, no such compacts have been approved by legislature or referendum.
U.S. Supreme Court redistricting cases
* ''
Colegrove v. Green'' (1946)
* ''
Baker v. Carr'' (1962) — federal courts may review redistricting of state legislative districts
* ''
Gray v. Sanders'' (1963) — 14th Amendment's equal protection clause requires “one person, one vote” standard
* ''
Wesberry v. Sanders'' (1964) — legislative districts for the U.S. House of Representatives must be composed, to the extent practicable, of equal numbers of eligible voters
''Burns v. Richardson''(1966)
* ''
Reynolds v. Sims'' (1964)
* ''
Gaffney v. Cummings'' (1973)
* ''
Karcher v. Daggett'' (1983)
* ''
Thornburg v. Gingles'' (1986)
* ''
Davis v. Bandemer'' (1986)
''Growe v. Emison''(1993)
''Voinovich v. Quilter''(1993)
* ''
Shaw v. Reno'' (1993)
''Johnson v. DeGrandy''(1994)
* ''
Miller v. Johnson'' (1995)
* ''
Bush v. Vera'' (1996)
* ''
Hunt v. Cromartie'' (1999)
* ''
Vieth v. Jubelirer'' (2004)
* ''
League of United Latin American Citizens v. Perry'' (2006)
* ''
Bartlett v. Strickland'' (2009)
* ''
Arizona State Legislature v. Arizona Independent Redistricting Commission'' (2015)
* ''
Gill v. Whitford'' (2018)
* ''
Benisek v. Lamone'' (2018 & 2019)
* ''
Rucho v. Common Cause'' (2019)
* ''
Allen v. Milligan'' (2023)
Alexander v. South Carolina State Conference of the NAACP(2023)
See also
*
Boundary commissions (United Kingdom)
In the United Kingdom, the boundary commissions are non-departmental public bodies responsible for determining the boundaries of parliamentary constituencies for elections to the House of Commons. There are four boundary commissions: one each f ...
*
United States congressional apportionment
Notes
References
Further reading
* . (About U.S. congressional districting)
External links
All About RedistrictingIncludes state criteria.
redistrictinginamerica.orgA comprehensive source for information about redistricting in all fifty states from th
Rose Institute of State and Local GovernmentMaptitude for Redistricting News
Congressional Apportionmentfrom the
Office of the Clerk at the
United States House of Representatives
The United States House of Representatives is a chamber of the Bicameralism, bicameral United States Congress; it is the lower house, with the U.S. Senate being the upper house. Together, the House and Senate have the authority under Artic ...
, including historical representation by state
District sizes and other data from 1900-2000from the
United States Census
The United States census (plural censuses or census) is a census that is legally mandated by the Constitution of the United States. It takes place every ten years. The first census after the American Revolution was taken in 1790 United States ce ...
Government Redistricting Web Sitesfrom GovDocs at
Purdue University
Purdue University is a Public university#United States, public Land-grant university, land-grant research university in West Lafayette, Indiana, United States, and the flagship campus of the Purdue University system. The university was founded ...
Libraries, includes list of state websites
Public Mapping ProjectA Citizen's Guide to Redistricting, 2010 Edition downloadable
Reapportionment and Redistricting in the U.S.from th
ACE Project
* Rodriguez, Lori.
Getting point of redistricting" ''
Houston Chronicle
The ''Houston Chronicle'' is the largest daily newspaper in Houston, Houston, Texas, United States. it is the third-largest newspaper by Sunday circulation in the United States, behind only ''The New York Times'' and the ''Los Angeles Times''. ...
''. Saturday August 24, 1991. A25.
www.FloridaRedistricting.org*
*
The Redistricting Game - Where Do You Draw the LinesA simulation of how redistricting works. It uses the real US laws and practices and incorporates quotes from US political leaders.
Equal Population in Redistrictingincludes definition of equal population criteria fro
ACE Projects
{{USRedistrictinglaw