Congressional maps are enacted by the State General Assembly. The Governor can veto the plans.
The General Assembly can override a veto with a two-thirds vote. Republicans currently have veto-proof majorities in both chambers.
Missouri’s state legislative districts are enacted through a commission process. There are two separate commissions. The Senatorial Apportionment Commission is composed of ten members selected by each major party's state party committee. Each party committee nominates ten members and the Governor chooses five per party. The House Apportionment Commission is composed of 16 members selected by each major party's congressional district committees, which nominate two members per district (who may not share the same state legislative district), and the Governor selects one per district per party.
Missouri utilizes a State Demographer to draft and propose plans to the Commissions. The Demographer is selected from an applicant pool by the State Auditor and the majority and minority leaders of the Missouri Senate. The State Demographer must not have served in an elected, partisan position for four years before the appointment.
The State Demographer presents a redistricting plan and accompanying data to the people of the state, the Secretary of State, and the House Apportionment Commission no later than six months after the results of the census are tendered to the President or no later than six months after a court ruling declaring the state’s maps illegal.
The members of the Commission gather to elect officers no later than ten days after being sent the proposed maps by the State Demographer. The public is given three or more opportunities to comment on the proposed maps to the Commissioners. Alterations may be made to the proposed maps from the State Demographer with a seven-tenths vote. If there are no alterations, the original maps become law. Within two months of collecting the original map from the State Demographer, a final statement including both maps and data are sent to the Secretary of State. If either commission does not send the plan in time, the State Supreme Court appoints six appellate judges to draw the maps.
Source: Mo. Const. art. III, §§ 3, 7.
Kinds of Ballot Measures
Direct initiatives and all referendums are permitted to amend statutes. Direct initiatives are permitted to amend the state constitution. Legislatively initiated ballot measures may amend both statutes and the constitution.
There is a single-subject rule.
Initiative Subject Restrictions
Ballot measures must be constitutionally permissible.
The signature requirement for constitutional amendments is 8% of all legal voters in each of two-thirds of the congressional districts of the state, 5% for statutory amendments, and 5% for veto referendums. The number of legal voters is based upon the total vote for governor at the last general election preceding the petition filing. Therefore, at least 160,199 signatures are required for constitutional amendments, and 100,126 signatures are required for statutory amendments as well as referendums, but this number depends on the districts from which signatures are gathered. District information can be found here.
Initiative petitions must be submitted six months prior to the election in which the petition is to appear on the ballot (May 3, 2020). Referendum petitions must be submitted to the Secretary of State no more than 90 days after the adjournment of the session which passed the bill in question.
The circulation period for initiative petitions is 18 months.
Ballot Title and Summary
The ballot title and summary are written by the Secretary of State and approved by the Attorney General. Expedited reviews for titles and summaries are permitted.
A fiscal impact statement is required. Circulators must be at least 18 years of age and registered with the Secretary of State. There are no supermajority requirements. The General Assembly can amend or repeal a voter-approved statute, but must follow constitutional guidelines to amend or repeal amendments. Referendums cannot target laws making appropriations for the current expenses of the state government or emergency legislation. Initiatives are permitted on general election ballots, but not on primary or special election ballots or odd-year ballots.