Reapportionment occurs during the biennial legislative session following each Federal decennial census. The process primarily—but not exclusively—relies on the population figures gathered during the most recent census. Legislative districts are drawn and House and Senate seats are allocated to ensure that the populations of each district have relatively equal representation in both chambers of the State House.
Three entities are involved in the process: the General Assembly, the Legislative Apportionment Board, and municipal Boards of Civil Authority. The Legislative Apportionment Board is the only party to the process whose sole purpose is reapportionment. The Board is chaired by a special master who is appointed by the Chief Justice of the Supreme Court. Each political party that has had more than three members serve as members of the General Assembly for at least three of the five biennial legislative sessions since the previous census is represented by two members on the board—one appointed by the Governor and one appointed by the state party committee. Until 2010, the Board had five members with two representatives each from the Democratic and Republican parties. In 2010, the Board expanded to seven members for the first time with the addition of two members from the Progressive party.
Apportioning the House of Representatives
To apportion the 150-member House of Representatives, the Legislative Apportionment Board first drafts an initial apportionment plan that draws on advice provided by local Boards of Civil Authority. The Legislative Apportionment Board's proposal outlines "initial districts." Initial districts can be one-member, two-member, or multi-member representative districts. The Board then submits this proposal to the General Assembly. The General Assembly typically revises the plan and then solicits input from the appropriate Boards of Civil Authority on how best to subdivide any multi-member districts into one- and two-member districts (a House district can only be represented by one or two representatives at the most). Drawing on this information, the General Assembly then enacts the final House apportionment scheme for the ensuing decade.
Apportioning the Senate
The method for apportioning the 30-member Senate is similar. The Legislative Apportionment Board drafts a proposal which is then submitted to the General Assembly. The General Assembly typically revises the proposal and enacts the system of senatorial districts for the next ten years. Boards of Civil Authority have no formal role in the apportionment of the Senate.
Changes in the Process
Like most government functions, the apportionment process has changed over time. Most significantly, the General Assembly has asserted more control over the process while the role of the Legislative Apportionment Board has been reduced. In 1992, the General Assembly enacted legislation that required the Board to submit a "proposal for reapportionment" rather than "a plan for reapportionment." The same legislation shifted the responsibility for reviewing proposals submitted by Boards of Civil Authority to subdivide multi-member districts from the Legislative Apportionment Board to the General Assembly. The General Assembly also assumed the responsibility for revising apportionment plans that are overturned by the courts.