Advertise Here

Deliver your message to thousands of readers every day.

Our readers are influential opinion makers - politicians, journalists and activists.

Our latest headlines

The Ballot Initiative Process in California Doesn’t Have to be Junked: It Can Be Reformed
What if California Had a Normal Government by Which It Addressed the Budget Deficit?
Sierra Club California Thanks Governor, Attorney General, and Air Resources Board for Upholding Clean Air Rules—Says to Automakers: Don't Be "Climate Chickens"
The "Year of Health Reform" in California: Take Two--Lessons for the Next Attempt
Budget Confusion in California: How Big a Gap Do You Want It to Be?
Preschool Reform Package is Alive and Well in the California Legislature
Prop 98: A Cardboard Box for Your Troubles

About Us

The California Progress Report is published by Frank D. Russo, a longtime observer of and participant in California politics.

About Frank Russo.
About California Progress Report.

Got a news tip? Want to write a guest column? Contact Frank here.

Advanced Imaging of California Precincts Shows Nuanced Landscape

By David Latterman
Principal
Fault Line Analytics

The California Political Precinct Index (CPPI) is an ongoing project by Fall Line Analytics to better characterize detailed political voting trends in California. The CPPI is a precinct-level index which ranks each California precinct on a 0-10 0 political scale, with 0 representing the most ‘conservative’ precincts and 100 representing the most ‘liberal’ precincts’.

Taking the methodology from the well-known and highly-accurate San Francisco Progressive Voter Index, the CPPI is created by performing a factor analysis on the results of several ballot measures for every California precinct. These measures can be interpreted on a left-right ideological scale, which when taken together, reveal inherent voting patterns of the precinct. Because the precinct change in most California counties from year to year, for the CPPI only issues from 2004 were used in this initial index.

The resulting index reveals political patterns in California that have rarely been seen at so detailed a level. We clearly understand the ‘liberal coast and conservative inland’ phenomenon, but now we can see subtle nuances throughout the state; for instance, variations between the coastal cities or the towns along Rt. 99 in the Central Valley.

When the CPPI is aggregated into larger geographies like counties, California Assembly Districts, or Congressional Districts, we can see big-picture voting trends. Looking at the average CPPI scores for Assembly districts, we see very clearly how left-leaning Districts vote Democrat, and right-leaning Districts vote Republican. There is also a transition area where districts are more up for grabs, and a party not in power could claim a seat from the sitting Assemblyperson. This technique works for any district configuration, and can also work for primaries when we get a sense of which districts lean toward the extremes for their parties and which of those lean more centrist.

Perhaps the most powerful application of the CPPI is the ability to breakdown the demographic and registration characteristics of each precinct. In our report, for example, we show differences within the Latino community through various Counties in California. With over 20,000 precincts as a sample size, we can perform advanced statistical analyses on a host of demographic variables to see what makes parts of California tick politically. We can also incorporate local ballot measures and candidate races to take a deeper look at specific political geographies.

With our ongoing project, we plan to add other years’ data to the CPPI, and accommodate changing precinct lines to maintain geographic consistency. But even at this level, the CPPI is a powerful new tool to examine the political goings-on in California!

David Latterman is the Principal of Fall Line Analytics, a San Francisco-based polling and political research firm. Latterman has spent the last several years using advanced statistical techniques and GIS mapping to paint detailed political pictures of many localities throughout California and the US. He also serves as a political analyst for several Bay Area media outlets. Latterman has advanced degrees from UNC Chapel Hill and UC Berkeley in geology and public policy.

Posted on June 19, 2007

Comments

Thanks for doing this important research.

Posted by: David Greene at June 21, 2007 10:11 AM

Get Email Updates

Want the California Progress Report by email? Once a week, we'll send you the latest and greatest headlines.

Stat tracker