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Fact Sheet · June 2011

California’s 2011 Redistricting: The Preliminary Plan

Eric McGhee

  • California’s current voting districts have been highly controversial.
    After every new census, California is legally required to adjust its district boundaries to make them equal in population and to meet certain requirements for minority representation under the Federal Voting Rights Act. Until recently, the state legislature has had primary initial responsibility for every redistricting. In 2001, it adopted a set of sometimes strange and contorted redistricting maps that prompted a decade of criticism and debate. The districts met the legal requirements but were drawn to be highly uncompetitive and to protect incumbent legislators. Only seven seats have changed partisan control in the 612 races of the last four general election cycles, despite high turnover nationally in several of those years.
  • The legislature’s redistricting has prompted an ambitious reform effort.
    In the wake of complaints about the 2001 redistricting, voters passed Propositions 11 in 2008 and 20 in 2010, placing responsibility for drawing districts in the hands of an independent citizens commission. The citizens were chosen through a complex process designed to encourage impartiality and independence from the political establishment. The commission has been working since December 2010 to fulfill its mandate and has just released a set of draft plans.
  • The commission’s draft plans provide greater competition within districts.
    A common definition of a competitive seat is one that falls between a five-point registration advantage for Republicans and a ten-point advantage for Democrats (reflecting the fact that Democrats are more likely to cross party lines). By this measure, the new districts are more competitive than the old ones. There are an additional seven competitive seats in the California Assembly (16 vs. 9), four seats in the California Senate (7 vs. 3) and five in the U.S. House of Representatives (9 vs. 4). For reference, the Democrats have an average registration advantage of 13 points for the state as a whole, so a certain number of uncompetitive districts cannot be avoided.
  • The draft plans show no clear signs of partisan gerrymandering, either with the districts themselves …
    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 a result in the draft plans. The number of districts that at least lean Democratic in terms of registration is about the same in the Assembly (55 after vs. 53 before) and Senate (29 after vs. 28 before), though Democrats do “gain” five seats (38 after vs. 33 before) in the U.S. House of Representatives.
  • … 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. The commission did not have any information about where incumbents live, although this sort of gerrymander might have occurred by accident. However, in contrast to the Democratic party’s advantage in seats, Democratic incumbents are actually a little more likely to be drawn into seats with fellow partisans: 32 out of 112 Democratic incumbents (29%) have suffered this fate, compared to 13 out of 61 Republicans (21%). 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 (-5% R, -2% D), and U.S. House (-6% 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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