Fixing prison-based gerrymandering after the 2010 Census: California

50 State Guide, March 2010

Impact at the state level
Impact at the local level
California law says a prison cell is not a residence
Additional resources

Prison-based gerrymandering violates the constitutional principle of “One Person, One Vote.” The Supreme Court requires districts to be based on equal population in order to give each resident the same access to government. But a longstanding flaw in the Census counts incarcerated people as residents of the prison location, even though they can’t vote and aren’t a part of the surrounding community.

When legislators claim people incarcerated in their districts are legitimate constituents, they award people who live close to the prison more of a say in government than everybody else.

Impact at the state level:

  • Los Angeles County contains 28% of California’s population, but 34% of the state’s prisoners come from the county. The political effect of this disproportionate incarceration rate is magnified by the fact that few prisoners are incarcerated in Los Angeles County — the county contains only 3% of the California’s state prison cells.
  • After the 2000 Census, California’s Congressional, Assembly and Senate districts were drawn to contain the same population of 639,088, 423,395 and 846,791 people each, respectively. Often states have a small population deviation between districts, but only one other state (Illinois) choose to prioritize population equality and draw all districts exactly the same size. Yet, this effort at population equality failed due to a flaw in the Census data used to draw the districts, as illustrated by a cluster of districts in the Central Valley:
    • 8.6% of the 30th Assembly district was incarcerated in state prisons.
    • 5.7% of the 20th Congressional district was incarcerated in state prisons.
    • 4.3% of the 16th Senate district was incarcerated in state prisons.
    In each of these districts, every group of 91 to 94 people were given as much influence in Sacramento as 100 people from any other district that is not itself padded with large prison populations.
  • Crediting many of California’s incarcerated people to a few locations, far away from home, enhances the political clout of the people who live near prisons, while diluting the voting power of all other Californians.

Impact at the local level:

  • The majority of California counties with large prisons rejected the Bureau’s 2000 Census prison counts and drew fair districts without regard to the prison population. These counties include: Amador, Del Norte, Imperial, Kern, Kings, Lassen, Madera, Monterey, San Luis Obispo and Tuolumne Counties.
  • In Lassen County, including the prison population after the 2000 Census would have meant a district that was entirely disenfranchised prisoners with no possibility of representation. In Kern County, the County Clerk told us that the prison population was excluded because “prisoners can’t vote and don’t receive local services.”
  • Counties with smaller prison populations (relative to their county populations) often failed to notice and correct the Census Bureau’s prison miscount. After the 2000 Census, 8% of one county district in Marin County is incarcerated, and 11.3% of Solano County District 4 is incarcerated at the CSP Solano and California Medical Correctional Facility. As a result, every group of 9 people who live in Solano’s District 4 were granted as much influence as 10 people in other districts.

California law says a prison cell is not a residence:

  • “A person does not gain or lose a domicile solely by reason of his or her presence or absence from a place while… kept in an almshouse, asylum or prison.” (California Election Code §2025.)


  • Ideally, the U.S. Census Bureau would change where it counts incarcerated people. They should be counted as residents of their home — not prison — addresses. There is no time for that in 2010, but California should ask the Census Bureau for this change for 2020.
  • After the 2010 Census, the state and its local governments should, to the degree possible, count incarcerated people as residents of their home communities for redistricting purposes. Where that is not feasible, incarcerated people should be treated as providing unknown addresses instead of being used to pad the legislative districts that contain prisons.

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