A New Way to Look at California Politics

David Latterman
Associate Director for the Leo T McCarthy Center for Public Service and Common Good, University of San Francisco.

We all like to look at California politics by who wins and who loses.  Democrats win here, Republicans win there (albeit fewer of them), but this doesn’t always tell us what Californians actually think when they vote.  Ballot measure results help, but it is still an incomplete picture.  Even within important categories like party registration and ethnicity, there is a great deal of ideological diversity.  Understanding the nuances of how people think can greatly affect how academics, consultants, and political watchers view the statewide electorate.

The California Political Precinct Index (CPPI) is single-number political index of nearly every voting precinct in California – over 20,000 in all.  This index was first created this in 2007, but after revising the methodology on joining precincts from year to year, we have a new 2012 version below that provides the highest-resolution look available of the California political picture.

The index itself is a 0-100 scale of the ideological leaning of a precinct, where lower numbers represent the most conservative precincts and higher numbers represent the most liberal precincts.  The CPPI is created from an algorithm using several ballot measures over the 2008 and 2010 elections.  These ballot measures, like same-sex marriage and alternative fuel bonds, have clear left-right ideological underpinnings that nearly all people working in politics understand.

The CPPI can be used to measure many aspects of the California electorate, by looking at election results, or by correlating it with countless demographic or registration categories.  These are some of the things we found:

  • There is a strong correlation to a precinct’s CPPI and the margin by which a representative wins his or her office.  That is, the higher the CPPI, the more we see Democrats win by (and vice versa for low CPPI scores and Republicans).  This pattern is consistent for both state offices and Congress.
  • We all understand the standard coast-liberal /inland-conservative model of California politics, but we also see how density comes into play.  Urban areas are more liberal than the less dense suburbs and exurbs, but all over the state, settlements are more liberal than surrounding areas.  Even in the Central Valley, small towns vote more liberal than regions outside of them.
  • There is a strong positive correlation with heavily-Latino precincts and CPPI.  However, we see that on some social issues like same-sex marriage and abortion, Latinos vote more conservatively than may be expected given an otherwise liberal voting record.
  • San Francisco (of course) is the most liberal county, followed by Santa Cruz and Alameda Counties.  Modoc is the most conservative county, followed by Glenn and Colusa.  The six most liberal counties are in the Bay Area.

Soon, we’re going to be looking at the new Assembly, Senate, and Congressional lines to help predict how the primary elections are going to go.  We’ll also be able to estimate which parts of the state will support the various fiscal measures we’ll be seeing this fall.  Having the CPPI adds a powerful new tool to help understand California’s complex political landscape.


The link to the original CPPI report can be found here.  

Comment on this article

Please note, statements and opinions expressed on the Fox&Hounds Blog are solely those of their respective authors and may not represent the views of Fox&Hounds Daily or its employees thereof. Fox&Hounds Daily is not responsible for the accuracy of any of the information supplied by the site's bloggers.