California Republicans are struggling this year to find a candidate who can beat Gov. Jerry Brown, state polls show. That's partly due to Brown's popularity and partly due to the shrinking proportion of the state's voters registered as Republicans.
About 28.6% of the state's voters are registered as Republicans, down from 35.7% a decade ago, according to the latest figures from the California Secretary of State. The proportion of voters registered as Democrats -- 43.5% -- has fluctuated during that period but today stands equal to where it was in 2004.
The percentage of voters declining to state a party preference -- 21.1% -- has grown significantly. If the trends of the next decade mirror the last, "no party preference" voters will outnumber Republicans in California by 2024.
Traditionally Democratic areas like San Francisco and Marin counties saw the largest proportional drop in Republican voters. No county in the state is now majority Republican.