Redistricting Criteria

4/23/2019

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When redistricting, state legislatures or redistricting commissions are provided certain criteria with which to draw the lines. These criteria are intended to make the districts easy to identify and understand, and to ensure fairness and consistency.

All states must comply with the federal constitutional requirements related to population and anti-discrimination. For congressional redistricting, the Apportionment Clause of Article I, Section 2, of the U.S. Constitution requires that all districts be as nearly equal in population as practicable, which essentially means exactly equal. For state legislative districts, the Equal Protection Clause of the 14th Amendment to the U.S. Constitution requires that districts be substantially equal. Some say that 10 percent deviation in population from one district to the next is a safe standard. However, that has not proven to be a guaranteed protection from court scrutiny or revision. Several states have provided for their own deviation standard. For instance, Colorado prohibits districts from having a population deviation above 5 percent (Colo. Const. Art. V, § 46).

In addition to population equality, Section 2 of the Voting Rights Act of 1965 prohibits plans that intentionally or inadvertently discriminate on the basis of race, which could dilute the minority vote.

In addition to these mandatory standards set out by the U.S Constitution and the Voting Rights Act, states are allowed to adopt their own redistricting criteria, or principles, for drawing the plans. Principles, or criteria, may be found in state constitutions or statutes or be adopted by a legislature, chamber, or committee, or by a court that is called upon to draw a plan when the legislative process fails. 

These traditional districting principles (or criteria) have been adopted by many states:

  • Compactness: Having the minimum distance between all the parts of a constituency (a circle, square or a hexagon is the most compact district).
  • Contiguity: All parts of a district being connected at some point with the rest of the district.
  • Preservation of counties and other political subdivisions: This refers to not crossing county, city, or town, boundaries when drawing districts.
  • Preservation of communities of interest: Geographical areas, such as neighborhoods of a city or regions of a state, where the residents have common political interests that do not necessarily coincide with the boundaries of a political subdivision, such as a city or county.
  • Preservation of cores of prior districts: This refers to maintaining districts as previously drawn, to the extent possible. This leads to continuity of representation.
  • Avoiding pairing incumbents: This refers to avoiding districts that would create contests between incumbents. 

These emerging criteria have been considered and adopted in a few states since 2000:

  • Prohibition on favoring or disfavoring an incumbent, candidate or party. The prohibition in a given state may be broader, covering any person or group, or it may be limited to intentionally or unduly favoring a person or group. Details on these prohibitions are included in the state descriptions below. 
  • Prohibition on using partisan data: Line drawers, whether they be commissioners (California and Montana), nonpartisan staff (Iowa), or legislators (Nebraska), are prohibited from using incumbent residences, election results, party registration, or other socio-economic data as an input when redrawing districts. 
  • Competitiveness: Districts having relatively even partisan balance, making competition between the two major parties more intense. This criterion typically seeks to avoid the creation of “safe” districts for a particular party. For instance, the Arizona constitution (cited below) states that “to the extent practicable, competitive districts should be favored where to do so would create no significant detriment to the other goals.” 

This future criterion has been adopted by Ohio for legislative districts beginning in 2021:

  • Proportionality: The statewide proportion of districts whose voters, based on statewide state and federal partisan general election results during the last ten years, favor each political party shall correspond closely to the statewide preferences of the voters. 
     

For details on state-specific criteria relating to who may drawing plans, what data may be used and the review process, other than districting principles, see this chart.

Another approach to Districting Principles for 2010 and beyond, please click here

The box allows you to conduct a full text search ortype the state name.

State Redistricting Criteria
STATE LEGISLATIVE OR CONGRESSIONAL CRITERIA CITATION

Alabama

Legislative

 

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

 

Ala. Const. Art. IX, §§ 198-200

 

Reapportionment Comm. Guidelines,  May 2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Protection of Incumbents

Alaska

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Alaska Const. Art. VI

Congressional

Only one congressional district

Arizona

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

Prohibited: Favor or Disfavor an Incumbent or Candidate, Use Partisan Data

Ariz. Const. Art. 4, pt. 2, § 1

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

Prohibited: Favor or Disfavor an Incumbent or Candidate, Use Partisan Data

Arkansas

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts

Allowed: Avoid Pairing Incumbents

 Ark. Const. Art. 8

 

Redistricting Criteria Approved by the Courts, Ark. Bd. of Apportionment (last visited Mar. 19, 2018)

 

 

 

 

Congressional

Required: No requirements>

California

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party; Use Partisan Data

Cal. Const. Art. 21, § 2

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party; Use Partisan Data

Colorado

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

Colo. Const. art. V, §§ 46-48.3, as amended Nov. 6, 2018

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

 

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

Connecticut

Legislative

Required: Contiguous, Preserve Political Subdivisions

Conn. Const. Art. III, § 3, as amended by Article II, §1, and Article XV, §1, of the Amends. to the Const. of Conn.;

Conn. Const. Art. III, § 4, as amended by Article II, §2, and Article XV, §2, of the Amends. to the Const. of Conn.;

Conn. Const. Art. III, § 5, as amended by Article XVI, §1, of the Amends. to the Const. of Conn.

Congressional

Required: No Requirements

Delaware

Legislative

Required: Contiguous

Prohibited: Unduly Favor a Person or Party

Del. Code tit. 29, § 804

Congressional

Only one congressional district

Florida

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor or Disfavor a Party or Incumbent

Fla. Const. Art. III, §§ 20, 21

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor or Disfavor a Party or Incumbent  

Georgia

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

 

Ga. Const. Art. III, § 2, Para. II

 

2011 Guidelines: House, Senate  

 

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

Hawaii

Legislative

Required: Compact, Contiguous, Preserve Communities of Interest

Prohibited: Unduly Favor a Person or Party

Hawaii Const. Art. IV, § 6

 

Hawaii Rev. Stat. § 25-2(b) (1)-(6)

 

 

 

Congressional

Required: Compact, Contiguous, Preserve Communities of Interest

Prohibited: Unduly Favor a Person or Party

Idaho

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Protect a Party or Incumbent

Idaho Const. Art. III, § 5

 

Idaho Code § 72-1506

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Protect a Party or Incumbent

Illinois

Legislative

Required: Compact, Contiguous

Ill. Const. Art. IV, § 3

 

Congressional

Required: No Requirements

Indiana

Legislative

Required: Contiguous

Ind. Const. Art. 4, § 5

Congressional

Required: No Requirements

Iowa

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor a Party, Incumbent, Person or Group; Use Partisan Data

 

Iowa Const. Art. III, §§ 34 & 37

 

Iowa Code § 42.4

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor a Party, Incumbent, Person or Group; Use Partisan Data

Kansas

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Avoid Pairing Incumbents

 

Kan. Const. Art. 10, § 1

 

Guidelines & Criteria for 2012 Kansas Cong. & Leg. Redistricting, Kansas Leg. Research Dept., Jan. 9, 2012

Congressional

Required: Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts

Kentucky

Legislative

Required: Contiguous, Preserve Political Subdivisions

 

Ky. Const. § 33

 

Criteria & Standards for Cong. Redistricting, Interim Joint Comm. on State

Government, Subcomm. on Redist., July 11, 1991

Congressional

Required: Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Louisiana

Legislative

Required: Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts

 

 

 

 

La. Const. Art. III, § 6

 

Committee Rules for Redistricting, La. House Comm. on House and Gov’tal Affairs, Jan. 19, 2011

 

Committee Rules for Redistricting, La. Senate Comm. on Senate and Gov’tal Affairs, Feb. 16, 2011

Congressional

Required: Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts

Maine

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

 

Me. Const. Art. IV, Part First, § 2

 

Me. Rev. Stat. tit. 21A, §§ 1206, 1206-A

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Maryland

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Md. Const. Art. III, § 4;

 

Congressional

Required: No Requirements

Massachusetts

Legislative

Required: Contiguous, Preserve Political Subdivisions

Mass. Const. Art. CI, as amended by Art. CIX

Congressional

Required: No Requirements

Michigan

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

Mich. Const. Art. IV, § 6, as amended Nov. 6, 2018

Mich. Comp. Laws §§ 3.63, 4.261, 4.261a

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

Minnesota

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

Prohibited: Intentionally Favor or Disfavor Incumbent

Minn. Const. Art. IV, §§ 2-3

 

Minn. Stat. § 2.91

 

Order Stating Redistricting Principles & Requirements for Plan Submissions, Hippert v. Ritchie, No. A11-152 (Minn. Spec. Redist. Panel Nov. 4, 2011)

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Mississippi

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Miss. Code §5-3-101

 

Criteria for Leg. and Cong. Redist., Standing Joint Leg. Comm. on Reapport. & Standing Joint Cong. Redist. Comm., Apr. 5, 2012

 

Analysis of Factors Considered, Smith v. Hoseman, No. 3:01-cv-855 (S.D. Miss., Dec. 19, 2011) 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

Missouri

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

 

Mo. Const. art. III, § 3(c), § 7, as amended Nov. 6, 2018

 

 

 

Congressional

Required: Compact, Contiguous

Montana

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Intentionally Favor Party or Incumbent, Use Partisan Data (except as required by a court in drawing a remedy)

 

Mont. Const. Art. V, § 14

 

Mont. Code Ann. § 5-1-115

 

Congressional and Legislative Redistricting Criteria 

Districting & Apport. Commis., May 28, 2010

 

Congressional

Only one congressional district

Nebraska

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts

Prohibited: Intentionally Favor Party, Group or Person; Use Partisan Data

 

Neb. Const. Art. III, § 5

 

Leg. Res. No. 102, Apr. 8, 2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts

Prohibited: Protect Incumbent, Use of Partisan Data

Nevada

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Avoid Pairing Incumbents

 

Nev. Const. Art. 4, § 5

 

N.R.S. Ch. 304, App.

 

Order Re: Redistricting, Guy v. Miller, No. 11-OC-42-1B (1st Jud. Dist., Carson City Sept. 21, 2011) 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Avoid Pairing Incumbents

New Hampshire

Legislative

Required: Contiguous, Preserve Political Subdivisions

N.H. Const., Part Second, House of Representatives, Arts. 9, 11, 11-a

N.H. Const., Part Second, Senate, Arts. 26, 26-a

Congressional

Required: No Requirements

New Jersey

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

N.J. Const. Art. IV, § 2

 

 

Congressional

Required: No Requirements

New Mexico

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Preserve Cores of Prior Districts, Avoid Pairing Incumbents

 

N.M. Stat. Ann. § § 2-7C-3,

 2-8D-2

 

Guidelines for the Development of State & Cong. Redistricting Plans, Legislative Council, Jan. 17, 2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Preserve Cores of Prior Districts, Avoid Pairing Incumbents

New York

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts, Competitive

Prohibited: Intentionally Favor or Disfavor Incumbent, Candidate or Party 

N.Y. Const. Art. III, § 4 & 5

 

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts, Competitive

Prohibited: Intentionally Favor or Disfavor Incumbent, Candidate or Party

North Carolina

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest,

Allowed:  Avoid Pairing Incumbents, Use Partisan Data

Prohibited: Use Racial Data

N.C. Const. Art. II, §§ 3 & 5

 

 

N.C. House and Senate Plans Criteria,

Sen. Comm. on Redist. & House Select Comm. on Redist., Aug. 10, 2017

 

N.C. Congressional Plan Criteria, Joint Select Comm. on Congressional Redist., Feb. 16, 2016

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Allowed:  Avoid Pairing Incumbents, Use Partisan Data

Prohibited: Use Racial Data

North Dakota

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts

 

N.D. Const. Art. IV, § 2

 

N.D. Cent. Code § 54-03-01.5

 

 

Congressional

Only one congressional district

Ohio

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Cores of Prior Districts (until Jan.1, 2021), Proportional

Prohibited: Favor an Incumbent or Party

Ohio Const. Art. XI, §§ 3, 6, 7, 9, 10, 11; Art. XIX, §§1, 2

 

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Prohibited: Favor an Incumbent or Party

Oklahoma

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Preserve Cores of Prior Districts, Avoid Pairing Incumbents

Okla. Const. Art. 5, § 9A

 

2011 Redistricting Comm. Guidelines for Redistricting, House Redist. Comm., Feb. 14, 2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Preserve Cores of Prior Districts, Avoid Pairing Incumbents 

Oregon

Legislative

Required: Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor Party, Incumbent or Person

Or. Const. Art. IV, § 7

 

Or. Rev. Stat. § 188.010

Congressional

Required: Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor Party, Incumbent or Person

Pennsylvania

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

Penn. Const. Art. II, § 16

 

Order, League of Women Voters of Pa. v. Pa., No. 159 MM 2017 (Pa. Jan. 22, 2018)

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Rhode Island

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

R.I. Const. Art. VII, § 1;

 Art. VIII, § 1

 

2011 R.I. Laws chs. 100, § 1; 106, § 1

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

South Carolina

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts, Avoid Pairing Incumbents

 

2011 Redist Guidelines, Sen. Jud. Comm., Apr. 13, 2011

 

2011 Guidelines & Criteria for Leg. & Cong. Redistricting, House Jud. Comm. Sub. on Election Laws, Apr. 28, 2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Preserve Cores of Prior Districts,

 Avoid Pairing Incumbents

South Dakota

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

 

S.D. Const. Art. III, § 5

 

S.D. Codified Laws § 2-2-41

 

 

Congressional

Only one congressional district

Tennessee

Legislative

Required: Contiguous, Preserve Political Subdivisions

Tenn. Code §§ 3-1-102, 3-1-103

Congressional

Required: No Requirements

Texas

Legislative

Required: Contiguous, Preserve Political Subdivisions

Tex. Const. Art. III, §§ 25, 26

Congressional

No Additional Requirements

Utah

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

 

Utah Code § 20A-19-201, as added Nov. 6, 2018

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Prohibited: Intentionally Favor or Disfavor an Incumbent, Candidate or Party

Vermont

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

Allowed: Avoid Pairing Incumbents

 

Vt. Const. Ch. II, §§ 13 & 18

 

Vt. Stat. tit. 17, ch. 34A, §§ 1903, 1906b, 1906c

 

Congressional

Only one congressional district

Virginia

Legislative

Required: Compact, Contiguous, Preserve Communities of Interest

 

Va. Const. Art. II, § 6

 

Va. Code § 24.2-305

 

House Criteria, House Comm. on Privileges & Elections,

Comm. Res. 1, Mar. 25, 2011

Senate Criteria, Senate Comm. on Privileges & Elections,

Comm. Res. 1, Mar. 25, 2011

Congressional Criteria, Joint Reapport. Comm., Aug. 17, 2015

Congressional

Required: Compact, Contiguous, Preserve Communities of Interest

Washington

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

Prohibited: Intentionally Favor or Disfavor a Party or Group

 

Wash. Const., Art. II, §§ 6, 43

 

Wash. Rev. Code § 44.05.090

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest, Competitive

Prohibited:  Intentionally Favor or Disfavor a Party or Group

West Virginia

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions

 

W. Va. Const., Art. I, § 4;

 Art. VI, § 4

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

Wisconsin

Legislative

Required : Compact, Contiguous, Preserve Political Subdivisions

Wis. Const., Art. IV, §§ 3-5;

 

Congressional

Required: No Requirements

Wyoming

Legislative

Required: Compact, Contiguous, Preserve Political Subdivisions, Preserve Communities of Interest

 

Wyo. Const. Art. 3, §§ 3, 49

 

Redistricting Principles – 2011, Joint Corps., Elections & Political Subdivisions Interim Comm., Apr. 4,2011

Congressional

Required: Compact, Contiguous, Preserve Political Subdivisions

NOTE: Only one congressional district

Note: Information on the districting principles, or criteria, used by each state as it redrew legislative and congressional districts for the 2010 Census and beyond is available at Districting Principles for 2010 and Beyond.

About This NCSL Project

Redistricting is the process of redrawing state legislative and congressional district boundaries every 10 years by state legislatures following the decennial U.S. Census. NCSL helps prepare legislatures and others for the redistricting cycle with comprehensive information on redistricting law, technology and process. NCSL collects data and information on new legislative and congressional districts.

For more information, contact Wendy Underhill.

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