2010 Redistricting Deviation Table

1/15/2020
There are several methods of measuring the extent to which populations of all the districts in a plan vary, or differ collectively from the "ideal." The method expressed in the below table is "Overall Range."
 
Overall range is perhaps the most commonly used measure of population equality, or inequality, of all districts, which can be expressed as a percentage (relative) or the actual population numbers (absolute). The "range" is a statement of the population deviations of the most populous district and the least populous districts. (For example, if the ideal district population is 100,000, the largest district in the plan has a population of 102,000, and the smallest district has a population of 99,000, then the range is +2,000 and -1,000, or +2 percent and -1 percent.) The overall range is the difference in population between the largest and the smallest districts, expressed as a percentage or as the number of people. (In the preceding example, the "overall range" is 3 percent or 3,000 people.)
 
This information is current as of January 2012. If you would like to provide an update on the deviation numbers for your state's redistricting plans please email Wendy Underhill.
 
For more about population deviation, how the numbers are calculated, and data from the 2000 cycle, see NCSL's Redistricting Law 2010 publication on p. 47.
 
2010 Redistricting Deviation Table

State

2010 Congressional Plan

2010 State House Plan

2010 State Senate Plan

 

Ideal District Size

Percent Overall Range

Overall Range (# of people)

Ideal District Size

Percent Overall Range

Ideal District Size

Percent Overall Range

Alabama

682,819

0.0

1

45,521 

 1.98

136,564 

1.98 

Alaska*1

     

 17,756

4.25 

35,512 

2.97 

Arizona**

710,224

0.0

0

213,067

8.78

213,067

8.78

Arkansas

728,980 

.06 

 428

29,159 

8.36 

83,312 

8.2 

California

702,905

0.0

1

465,674

1.98

931,349

1.99

Colorado

718,457

0.0

1

77,372

4.98

143,691

4.99

Connecticut2

714,819 

 0.0

 1

23,670 

 5.99

 99,280

 9.79

Delaware*

     

21,901 

9.93 

42,759 

10.73 

Florida3

696,345

0.0

1

156,678

3.98

470,033

1.92

Georgia4

691,975 

0.0 

53,820 

1.98 

172,994 

1.84 

Hawaii5

 680,151

0.1 

691 

24,540 

21.57 

50,061 

44.22 

Idaho**

783,791

0.1

682

44,788

9.7

44,788

9.7

Illinois

712,813

0.0

1

108,734

0.0

217,468

0.0

Indiana

720,422

0.0

1

64,838

1.74

129,676

2.88

Iowa

761,589

0.0

76

30,464

1.93

60,927

1.65

Kansas

713,280 

0.0 

 15

22,716 

2.87 

70,986 

2.03 

Kentucky6

 723,228

 0.0

334

43,394 

11.62

 114,194

11.02

Louisiana

755,562

0.0

249

43,174 

9.89 

 116,240

9.86 

Maine

664,181 

0.0 

8,797 

 9.9

37,953 

9.51 

Maryland***7

721,529

0.0

1

122,813

8.87

122,813

8.87

Massachusetts

727,514

0.0

1

40,923

9.74

163,691

9.77

Michigan

705,974 

0.0

 1

 89,851

9.96 

260,096 

 9.79

Minnesota**

662,991

0.0

1

39,582

1.6

79,163

1.42

Mississippi

741,824

0.2

134

24,322 

9.95 

57,063 

9.77 

Missouri

748,616 

 0

 36,742

7.8 

176,145 

8.5 

Montana*8

     

9,894 

 5.44

19,788 

5.26 

Nebraska

608,780

0.0

1

N/A

N/A

37,272

7.39

Nevada

675,138

0.0

1

64,299

1.33

128,598

0.8

New Hampshire***

658,235 

0.0 

 4

3,291 

9.9 

54,853 

8.83 

New Jersey**

732,658 

 0.0

219,797 

 5.2

219,797 

5.2

New Mexico

686,393 

 0.0

29,417 

6.68 

 49,028

 8.7

New York

 717,707

0.0 

 1

 129,089

7.94 

307,356 

8.8 

North Carolina9

733,499 

0.0 

79,462 

9.97 

190,710 

 9.49

North Dakota*

     

14,310

8.86

14,310

8.86

Ohio10

721,032 

 0.0

 1

116,530 

16.44 

349,591 

9.2 

Oklahoma

750,270

0.0

1

37,142

1.81

78,153

2.03

Oregon

766,215 

0.0 

63,851 

3.1 

127,702 

 2.99

Pennsylvania11

705,688 

0.0 

 1

 62,573

 7.88

254,048 

7.96 

Rhode Island

526,284 

 0.0

 1

 14,034

4.98 

27,699 

5.01 

South Carolina

660,766 

 0.0

37,301 

4.99 

100,551 

9.55 

South Dakota*12

     

23,262**

9.64

23,262

9.47

Tennessee

705,123 

0.0 

 1

64,102

9.74

192,306

9.17

Texas

698,488

0.0

32

167,637

9.85

811,147

8.04

Utah13

690,971 

0.0 

 1

36,852 

0.0

95,306 

.01

Vermont*,***14

     

4,172 

18.8

20,858 

 18.01

Virginia

727,366

0.0

1

80,010

2.0

200,026

4.0

Washington**

672,454

0.0

19

137,236

.07

137,236

.07

West Virginia***

617,665

.79

4,871

18,530

9.99

109,000

10.00

Wisconsin

710,873 

 0.0

 1

 57,444

 .76

172,333 

.62 

Wyoming*

536,626

0.0

0.0

9,394

9.84

18,788

9.37

SOURCE: National Conference of State Legislatures, 2019

* State has only one Congressional seat.

** These states use multi-member districts, with two House seats elected in each Senate district.

*** These states use multi-member districts with varying numbers of senators (Vermont) or representatives (Maryland, New Hampshire, Vermont and West Virginia) in each district.

1. Alaska: Data from the unified plan adopted for elections in 2014.

2. Connecticut: Data for the Senate from the plan adopted for elections in 2016.

3. Florida: Data for the Senate from the plan adopted for elections in 2016.

4. Georgia: Data from the plans adopted for elections in 2016 (House) and 2014 (Senate).

5. Hawaii modifies the census counts for legislative plans; the modified numbers are used to apportion seats to the four basic island units (BIUs). Each unit has a separate target population for each chamber. The deviation numbers in the table reflect the range of all districts for that chamber. 

6. Kentucky: Data from legislative plans adopted for elections in 2014. 

7. Maryland has three House of Delegates districts nested within each Senate district; tehse three may be either a three-member district, or any combination of single-member or two-member districts. The ideal district size for the two-member districts is 81,875, with an overall deviation of 9.39%. The ideal district size for the single-member district is 40,938 with an overall deviation of 8.92%. 

8. Montana: Data from the legislative plans adopted for elections in 2014. 

9. North Carolina: Data from legislative plans finalized for elections in 2018. 

10. Ohio used a customized dataset for the legislative plans with numerous split blocks; this does not affect the ranges. 

11. Pennsylvania: Data from plans adopted for elections in 2014. 

12. South Dakota: Thirty-three of the state's 35 districts elect one senator and two House members, but the state also maintains two Senate districts split into four single-member House districts. These four districts have an ideal population of 11,631, with an overall deviation of 4.68%. 

13. Utah: These numbers reflect the legislative plans as enacted in 2011 using the census counts. Subsequent review by the state found several instances where local political boundaries were incorrect in the geography files. Deviations based upon updated block assignment files from the Census Bureau are 1.55% for the House and .39% for the Senate. 

14. Vermont split a census block, which affects the overall range for the House; it would be 19.07% using whole blocks. 

About This NCSL Project

Redistricting is the process of redrawing state legislative and congressional district boundaries every 10 years 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. 


For more information, contact: Wendy Underhill, NCSL Staff Liaison.