Editing Redistricting (section)

==Legislative representatives==
===Federal===
{{Further|United States congressional apportionment}}
[[File:2020 census reapportionment.svg|thumb|upright=.95|Allocation of districts following the [[2020 United States census|2020 census]].]]
[[File:USCongressionalRedistrictingPartisanControl2020.svg|upright=.95|thumb|Partisan control of congressional redistricting after the 2020 elections, with the number of U.S. House seats each state will receive.
{{legend|#2c82b6|Democratic control}}
{{legend|#d63f3f|Republican control}}
{{legend|#ecc61c|Split or bipartisan control}}
{{legend|#60c53a|Independent redistricting commission}}
{{legend|#c0c0c0|No redistricting necessary}}]]

Six states have a single representative in the [[United States House of Representatives]], because of their low populations.<ref>{{cite web |last1=U.S. Census Bureau |title=2020 Census: Apportionment of the U.S. House of Representatives |url=https://www.census.gov/library/visualizations/2021/dec/2020-apportionment-map.html |website=Census.gov |date=April 26, 2021}}</ref> These are [[Alaska]], [[Delaware]], [[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.<ref name="usc2ac">{{USC|2|2a(c)}}</ref>

In 25 states, the [[State legislature (United States)|state legislature]] has primary responsibility for creating a redistricting plan, in many cases subject to approval by the state [[Governor (United States)|governor]].<ref name="whodrawlinern"/> To reduce the role that legislative politics might play, thirteen states ([[Alaska]],{{efn|Since Alaska only has a single representative, its congressional redistricting laws are not currently in force.}} [[Arizona]], [[California]], [[Colorado]], [[Hawaii]], [[Idaho]], [[Michigan]], [[Missouri]], [[Montana]], [[New Jersey Redistricting Commission|New Jersey]], [[Ohio]], [[Pennsylvania]], and [[Washington (state)|Washington]]) determine congressional redistricting by an independent or bipartisan [[redistricting commission]].<ref name="NCSL-redistricting">{{cite web |url=http://www.ncsl.org/legislatures-elections/redist/2009-redistricting-commissions-table.aspx |title=2009 Redistricting Commission Table |publisher=[[National Conference of State Legislatures]] (NCSL) |date=June 28, 2008 |access-date=2013-09-06}}</ref> Five states: [[Maine]], [[New York (state)|New York]], [[Rhode Island]], [[Vermont]],{{efn|Since Vermont only has a single representative, its congressional redistricting laws are not currently in force.}} 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 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.<ref>[[Wesberry v. Sanders]], 376 U.S. 1, 18 (1964).</ref><ref name="usc2ac"/> Federal law (including the [[Constitution of the United States|Constitution]]) 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.<ref>[[League of United Latin American Citizens v. Perry]], 548 U.S. 399, 447 (2006).</ref> However, "mid-decade" redistricting proposals (such as what occurred in [[2003 Texas redistricting|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.<ref>{{Cite web |title=National Overview |url=https://redistricting.lls.edu/national-overview/ |access-date=2023-04-08 |website=All About Redistricting |language=en}}</ref>[[File:Congressional mid-decade redistricting map.png|thumb|The legality of mid-decade congressional redistricting in the United States]][[File:State legislative mid-decade redistricting map.png|thumb|The legality of mid-decade state-legislative redistricting in the United States]]

Apart from mid-decade redistricting initiated by state legislatures (as happened in [[2003 Texas redistricting|Texas]]), 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 [[Redistricting in Pennsylvania#2018: Pennsylvania Supreme Court invalidating the 2011 congressional districts|Pennsylvania]] or the redistricting that occurred in [[Redistricting in North Carolina|North Carolina]].<ref>[[League of Women Voters of Pennsylvania v. Commonwealth of Pennsylvania]], 181 A.3d 1083 (Pa. 2018)</ref>

===State===
State constitutions and laws also mandate which body has responsibility over drawing the state legislature boundaries.<ref>
{{cite web
|url=http://www.lib.purdue.edu/govdocs/redistricting.html
|title=Government Redistricting Web Sites
|publisher=Purdue University Libraries
|access-date=2009-08-25
|last=Blake 
|first=Aaron 
}}
</ref> In addition, those [[Local government in the United States#Municipal governments|municipal government]]s that are elected on a district basis (as opposed to an [[at-large]] basis) also redistrict.<ref>{{cite web |title=California Secretary of State: City and County Redistricting Process |url=https://www.sos.ca.gov/elections/helpful-resources/redistricting |website=www.sos.ca.gov |access-date=29 November 2021}}</ref>

===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.<ref>Apportionment Act of 1842, 5 Stat. 491.</ref><ref>Apportionment Act of 1862, 12 Stat. 572.</ref><ref>[[Vieth v. Jubelirer]], 541 U.S. 267, 276 (2004).</ref>

Each state can set its own standards for congressional and legislative districts.<ref>
{{cite web
|url=http://thehill.com/campaign-2008/redistricting-looms-over-2010-election-landscape-2009-06-13.html
|archive-url=https://web.archive.org/web/20090618070653/http://thehill.com/campaign-2008/redistricting-looms-over-2010-election-landscape-2009-06-13.html
|url-status=dead
|archive-date=June 18, 2009
|title=TheHill.com - Redistricting looms over 2010 landscape
|work= [[The Hill (newspaper)|The Hill]]
|access-date=2009-08-25
}}
</ref> 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.<ref>Miller, Jason C.,[http://ssrn.com/abstract=1635614 Community as a Redistricting Principle: Consulting Media Markets in Drawing District Lines] (July 6, 2010). Indiana Law Journal Supplement, Vol. 5, 2010.</ref>

Redistricting may follow other criteria depending on state and local laws:<ref name="ARCUSER">{{citation |title=ArcGIS is Making Redistricting More Efficient and Transparent |newspaper=ArcUser |url=http://www.esri.com/~/media/Files/Pdfs/news/arcuser/0518/arcuser-spring-2018.pdf|date=Spring 2018|pages=26}}</ref>
# compactness<ref name="cambridge.org">{{Cite journal |last1=Katz |first1=Jonathan N. |last2=King |first2=Gary |last3=Rosenblatt |first3=Elizabeth |date=2020 |title=Theoretical Foundations and Empirical Evaluations of Partisan Fairness in District-Based Democracies |url=https://authors.library.caltech.edu/records/awqcc-r3g16/files/S000305541900056Xsup001.pdf?download=1 |journal=American Political Science Review |language=en |volume=114 |issue=1 |pages=164–178 |doi=10.1017/S000305541900056X |s2cid=53991300 |issn=0003-0554}}</ref>
# [[Contiguity (probability theory)|contiguity]]
# equal [[population]]
# preservation of existing political communities
# partisan fairness<ref name="cambridge.org"/>
# racial fairness<ref>{{Cite book|title = The Politics of Congressional Elections|last = Jacobson|first = Gary|publisher = PEARSON Education|year = 2013|location = New Jersey|pages = 9}}</ref>