Detailed Description of Maine's Apportionment Process

Maine State Senate and House of Representatives District Apportionment


The Maine Constitution, in Article IV, Part First and Part Second, provides for the reapportionment of State Representative and State Senate Districts, respectively, in 2021 and every 10th year thereafter. The size of the districts is determined by dividing the number of Senators and Representatives into the number of inhabitants of the State, exclusive of foreigners not naturalized, according to the latest Federal Decennial Census, to determine a mean population figure for each Senate and Representative District.

Article IV, Part Third, section 1-A of the Constitution provides that the Legislature shall establish an Apportionment Commission within the first 3 calendar days after the convening of the Legislature in which apportionment is required. This Commission must develop, in accordance with the requirements of the Constitution, a plan for apportioning the House of Representatives, the Senate, or both. The apportionment plan of the Commission established under this section must be submitted to the Secretary of the Maine Senate (for the Senate apportionment) or the Clerk of the Maine House of Representatives (for the House apportionment) no later than June 1st of the year in which apportionment is required. The Legislature shall enact the submitted plan of the commission or a plan of its own by a vote of 2/3 of the Members of each House, by June 11th of the year in which apportionment is required.

In the event that the Legislature fails to make an apportionment, the Supreme Judicial Court shall make the apportionment within 60 days following the period in which the Legislature is required to act but fails to do so.

Because of delays in the release of 2020 U.S. Census Data, the Maine Supreme Judicial Court granted a petition by Legislative leaders to extend the state’s constitutionally mandated legislative redistricting timeline, allowing the Legislature to keep its redistricting powers despite census delays.

Under the new timeline, the Apportionment Commission had 45 days to come up with legislative maps after release of census data. Census data was released on August 12, 2021. The Commission delivered a report and an apportionment plan to the Legislature on September 27, 2021.  On Wednesday, September 29, 2021, the Legislature convened to and voted to approve the Commission's plan. It was signed into law by Governor Janet Mills on September 29, 2021.

U.S. Congressional District Apportionment

Title 21-A M.R.S.A., Maine Law on Elections, section 1206, provides for the apportionment of U.S. Congressional Districts. In 2021, and every 10 years thereafter, when the Secretary of State has received notification of the number of congressional seats to which the State is entitled and the Federal Decennial Census population count is final, the Legislative Apportionment Commission, as provided in Article IV, Part Third, section 1-A, shall review the existing congressional districts. If the districts do not conform to Supreme Judicial Court guidelines, the Commission shall reapportion the State into Congressional Districts.

Under Maine law, the Commission is supposed to submit its plan to the Clerk of the Maine House of Representatives no later than June 1st of the year in which apportionment is required. The Legislature shall enact the submitted plan of the Commission or a plan of its own in regular or special session by a vote of 2/3 of the members of each house by June 11th of the year in which the apportionment is required. If the Legislature fails to make an apportionment, the Supreme Judicial Court shall make the apportionment within 60 days following the period in which the Legislature is required to act but fails to do so.

Because of delays in the release of 2020 U.S. Census Data, the Maine Supreme Judicial Court granted a petition by Legislative leaders to extend the state’s statutory congressional redistricting timeline, allowing the Legislature to keep its redistricting powers despite census delays.

Under the new timeline, the Apportionment Commission had 45 days to come up with a proposal for congressional apportionment after release of the census data. Census data was released August 12, 2021.  The Commission delivered a report and an apportionment plan to the Legislature on September 27, 2021.  On Wednesday, September 29, 2021, the Legislature convened and voted to approve the Commission's plan. It was signed into law by Governor Janet Mills on September 29, 2021.

Implementation of the New Districts

Title 21-A, section 1207, requires the Secretary of State to implement the election districts established pursuant to the Maine Constitution or Title 21-A. The Secretary of State must inform the municipal clerks of the voting district or districts in which each municipality lies and provide district maps and narrative geographic descriptions of relevant election districts to those officials. The Secretary of State may resolve ambiguities concerning the location of election district lines consistent with requirements of Chapter 15 of Title 21-A.