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Fact Sheet · August 2011

California’s 2011 Redistricting: The Commission’s Final Plans

Eric McGhee

  • California’s districts, as drawn by the state legislature in 2001, prompted an ambitious reform effort.
    After every new census, all states are legally required to adjust their voting district boundaries to make them equal in population and to meet certain requirements for minority representation under the Federal Voting Rights Act. In California, the state legislature has traditionally been responsible for initiating the redistricting process. In 2001, it adopted a set of sometimes contorted redistricting maps that prompted a decade of criticism and debate. The districts met the legal requirements but were drawn to protect incumbent legislators rather than to be politically competitive. In response, voters have placed responsibility for redistricting in the hands of an independent citizens commission. The members of this commission were chosen through a process designed to encourage impartiality and independence from the political establishment.
  • The commission’s June 10 draft plans offered a larger number of competitive seats than the 2001 maps.
    The commission released its first set of draft plans on June 10. These maps included a larger number of potentially competitive seats, defined as those that fall between a five-point registration advantage for Republicans and a ten-point advantage for Democrats (reflecting the fact that Democrats are less likely to vote and more likely to cross party lines when they do). Across the 173 seats in all three plans (Assembly, Senate, and U.S. House of Representatives), the number of competitive seats doubled, from 16 to 32. The maps also offered a slight benefit to Democrats, which was offset somewhat by the uncertainty of competitive seats and a general disregard for the electoral safety of sitting incumbents in either party.
  • The final plans also offer more competitive seats than the 2001 maps, but fewer than the June 10 draft.
    The commission released its final maps on July 28. The plans once again include a larger number of competitive seats than under the maps from 2001: an additional two seats in the California Assembly (11 vs. 9), four in the California Senate (7 vs. 3), and six in the U.S. House of Representatives (10 vs. 4). Compared to the June 10 draft, there are five fewer competitive seats in the Assembly, the same number in the Senate, and one additional seat in the House.
  • The final plans also avoid partisan gerrymandering with the districts …
    When a party seeks to gain advantage through redistricting, it usually does so in one of two ways. The first is to try to ensure that the disadvantaged party “wastes” votes on larger victory margins in the seats it wins, thus claiming fewer seats overall for the same number of supporters. There is little evidence of such an attempt in the commission’s plans. The number of districts that at least lean Democratic in terms of registration is about the same in the Assembly (54 vs. 53 before) and Senate (29 vs. 28 before), although Democrats do “gain” six seats in the U.S. House of Representatives (39 vs. 33 before). Because the new Democratic-leaning seats are often competitive, the benefit for Democrats could easily prove elusive.
  • … or with the placement of incumbents in those districts.
    The second common means of gerrymandering is to dislodge incumbents of the minority party, either by putting two or more of them into the same district or by dramatically changing the districts they hold, so that reelection becomes difficult. Under the final maps, Democrats are about as likely as Republicans to be drawn into seats with fellow partisans: 39 out of 112 Democratic incumbents (35%) have suffered this fate, compared to 20 out of 61 Republicans (33%). Moreover, the average loss of safety, as measured by party registration, is about the same for Republican and Democratic incumbents in the Assembly (-3% R, 0% D), Senate (-3% R, -2% D), and House of Representatives (-3% R, -3% D).

Sources: 2010 Registration numbers: California Statewide Database. District lines: California Citizens Redistricting Commission.

Note: For current and proposed district maps, visit the California Citizens Redistricting Commission website at


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