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Overview: Missouri Redistricting Reform Proposal (Clean Missouri)

An overview of a proposed constitutional amendment to change the legislative redistricting process in Missouri.

Published: October 12, 2018

Clean Missouri is the citizen coalition behind the 2018 ballot proposal to amend the state constitution to require a nonpartisan state demographer to draw state legislative maps for the approval of Missouri’s politician redistricting commissions. If voters approve this amendment, the nonpartisan state demographer would draw legislative districts starting in 2021. A copy of the proposed amendment can be found here.

Key Features

What Maps the Demographer Will Draw

State legislative districts, for consideration by Missouri’s politician redistricting commissions

Current Redistricting Structure

Missouri currently has two legislative redistricting commissions that draw maps for the state house and senate respectively:

House apportionment commission

The congressional district committees of the two largest political parties separately nominate two individuals from each of Missouri’s eight congressional districts who do not live in the same state legislative district. These two lists of 16 Republican nominees and 16 Democratic nominees are submitted to the governor, who then selects one individual from each congressional district for each party. If either party committee fails to submit the list of nominees within sixty days after census data is released, the governor will appoint a member of his or her choice from the district for the party whose committee failed to make the nomination.

Senate apportionment commission

The state committee of the two political parties will each nominate ten individuals and submit the list of names to the governor who will appoint ten members, five from each party, to the commission to draw senate districts. If either party committee fails to submit a list within sixty days after the census data is released, the governor will appoint five members of his or her choice for the party whose committee failed to submit a list.

This ballot proposal would not change the composition of the commissions. Instead, it would add a nonpartisan state demographer who would draw the proposed house and senate boundaries for the approval by the commissions to the process. The commissions would then be responsible for hosting public hearings across the state and approving the map in accordance with the procedures outlined below.

How the Demographer is Selected

Any resident of the state may submit an application to the state auditor to become the nonpartisan demographer. The state auditor will send the majority and minority leaders of the senate a list of at least three applicants who have the qualifications and expertise to fulfill the position. The majority and minority leaders will jointly select an applicant to become the nonpartisan state demographer. If the senate leaders cannot agree on a candidate, then the leaders can each strike up to one-third of the applicants on the list, and the state auditor will randomly select an applicant from the remaining candidates.

Who is Eligible to Be the Demographer

To be eligible, an individual may not have served in a partisan elected position at least four years prior to appointment. The nonpartisan state demographer is disqualified from holding office as a member of the legislature for four years following his or her most recent redistricting maps.

How a Map Gets Approved

The legislative apportionment commissions approve the state house and senate maps. The commissions may make changes to the tentative redistricting plans proposed by the nonpartisan state demographer, but only if the changes are consistent with redistricting criteria and have been approved by at least seven-tenths of the commissioners. If no changes are made or approved, the tentative plan of apportionment and map of proposed districts created by the nonpartisan demographer will be final.

The Rules That Must Be Followed in Drawing a Map

The nonpartisan state demographer must follow a ranked order list of criteria while preparing legislative districting plans:

  1. Districts must be established on the basis of total population. The population of each district should be made as equal as practical.  
  1. Districts shall comply with the U.S. Constitution and other federal laws such as the Voting Rights Act.
  1. Districts may not be drawn with the intent of or have the effect of denying or abridging racial or language minorities an equal opportunity to participate in the political process or diminish their ability to elect representatives of choice, whether individually or in concert with others.
  1. Districts shall be designed to achieve both partisan fairness, and secondarily, competitiveness.  
  • Partisan fairness is defined as parties being able to translate their support into legislative representation with approximately equal efficiency. Competitiveness means parties’ legislative representation will be substantially and similarly responsive to shifts in the electorate’s preferences.   
  • To measure partisan fairness, the state demographer will calculate the average electoral performance of the two parties receiving the most votes the in the past three elections (determined by the total votes received by each party in the last three state-wide elections divided by the total votes cast for each party in these elections) and then calculate the total number of wasted votes for each party. Wasted votes are the votes received by winning candidate above the 50-percent threshold necessary to win and all the votes received by the losing candidate. The state demographer must ensure that the difference between the two parties’ total wasted votes divided by the total votes cast for the two parties is as close to zero as possible. 
  • To promote competitiveness, the demographer will use the electoral performance index to simulate elections where the hypothetical statewide vote shifts within one to five percent in favor of each party. In each of the simulated elections, the difference between the two parties’ total wasted votes divided by the total votes cast for the two parties, should be as close to zero as possible.
  1. Districts must be composed of contiguous territory.  
  1. Districts shall coincide with the political subdivisions of the state.
  1. Districts are preferably compact, but the preceding criteria take precedence over compactness when a conflict arises. Compact districts are defined as those that are square, rectangular, or hexagonal in shape to the extent allowed by natural or political boundaries.

Public Input and Transparency

Within ten days of receiving the tentative map, each commission will schedule at least three public hearings.


The state auditor is responsible for establishing the time frame and deadlines for the application and selection process.

Within ten days after the census data is released, the nonpartisan state demographer will begin preparing legislative districting plans.

Within six months after census data is released or, in the event a court invalidates a reapportionment plan, the nonpartisan state demographer will file a tentative plan of apportionment, a map of the proposed districts and the underlying demographic and partisan data to the secretary of state and the redistricting commissions.

Terms of Office

The nonpartisan state demographer will serve a five-year term and may be reappointed.


The proposal does not specify a source of funding.

A copy of the ballot proposal can be found here. A PDF version of this analysis can be found here

This is proposal overview is informational and does not imply endorsement by the Brennan Center for Justice.