Implications of California’s rapid increase in no party preference voter registration: substituting demographic characteristics for party affiliation as indicators of policy preference among party-unaffiliated voters

The number of California voters who are choosing not to register with one of the state's six recognized political parties has increased substantially over the last two decades, first surpassing Republican registration in mid-2018, and then to an all-time high of just over 28 percent of all registered voters in the state as of February 10, 2019. Unlike party-affiliated voters, the ideological leanings and policy preferences of these voters cannot be determined from voter registration rolls. Where campaigns could previously target Democratic- and Republican-registered households with liberal- and conservative-leaning messaging respectively, those campaigns will have to rely on other indicators to determine how to target those voters with messaging that aligns with their particular issue and candidate preferences. A linear regression analysis of the vote choices of party-unaffiliated voters in the 2008, 2012, and 2016 presidential elections shows that racial/ethnic minority status, age, and household income are fairly strong indicators of ideological preference.