Reapportionment data comes out Tuesday

California will learn Tuesday morning whether it gains, loses or keeps the same number of congressional seats in the next decade. Click here to watch the U.S. Census Bureau’s Tuesday reapportionment press conference online. It starts at 8 a.m. PST.

Reapportionment is the process under which the 435 seats in the House of Representatives are divided among the 50 states based on population figures gathered in the decennial census. Every state is initially assigned one seat, and a calculation called the Method of Equal Proportions is applied to the remaining 385 seats.  Watch a Census Bureau video on how the formula works here. Or view an interactive nationwide map here.

California has gained at least one seat every decade since 1930, but the leading reapportionment analysts at Virgina-based Election Data Services predict the Golden State will remain at 53 seats. Here’s a look at California history:

  • 1910, gains 3 seats
  • 1920, gains 0 seats
  • 1930, gains 9 seats
  • 1940, gains 3 seats
  • 1950, gains 7 seats
  • 1960, gains 8 seats
  • 1970, gains 5 seats
  • 1980, gains 2 seats
  • 1990, gains 7 seats
  • 2000, gains 1 seat

Reapportionment is different than redistricting, the process by which political boundaries are redrawn within a state after the census.

Californians are unusually well informed about redistricting these days, thanks to a series of successful ballot measures that  stripped the Legislature of the job of drawing its own boundary maps and turned it over to an independent redistricting commission. The commission settled on its final, 14-member roster on Wednesday. Click here for information about the new panel.

On Tuesday, the Census Bureau will announce total state populations in 2010 and run the national reapportionment formula.

The detailed numbers the Redistricting Commission needs to redraw California’s congressional, legislative and Board of Equalization boundaries will not emerge from the Census Bureau until probably the end of March. The bureau will start rolling out the detailed tables in February but California is usually at the tail-end of the schedule.

In the meantime, if you are a redistricting junkie and you are dying to look at some maps or look at analysis of where districts might have to move, check out the Claremont McKenna College Rose Institute redistricting site.  Its scholars have posted a great deal of analysis, including a Dec. 8 report called ‘The 2010 Census and California’s 2011 Redistricting.” UC-Berkeley has a fabulous site, too, called the Statewide Database.

Rose Institute experts say California’s population center continues to shift away from its traditional coastal metropolitan regions toward inland communities. For example, the Bay Area has grown at a rate less than 1 percent in the past decade, significantly lower than the statewide rate of 10.4 percent.

The introduction of the citizen’s redistricting commission could result in very different political maps, the institute’s report concluded.

“With California’s new Citizens Redistricting Commission now in charge of the state’s redistricting process, incumbent legislators will no longer be able to control the effects of regional changes in California’s population,” the study said.

Lisa Vorderbrueggen