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Blog Post · May 9, 2023

The Dynamics of Party Registration in the Golden State

photo - voting posters with people registering to vote

In recent years, California has become a much more Democratic state, with the party holding all statewide offices and supermajorities of the state legislature. Observers have begun to wonder whether Republicans are leaving California to avoid the policies of this Democratic majority. As it turns out, Republicans are slightly more likely to leave—but the greater impact has come from new California voters registering without a party preference rather than as Republican.

Between the 2012 and 2020 presidential elections, the registered population grew about 20%—roughly twice as fast as the voting-eligible population. We can identify the characteristics of party gains and losses by merging older copies of the voter registration file to newer ones.

About 4.2 million new Democrats registered over this time, while 3.5 million new voters registered as some other party or No Party Preference (NPP), and about 1.8 million as Republicans. That makes the new registrants about as Democratic as existing ones in 2012 (44% for each), but far less likely to be Republican (19% vs. 29%), and far more likely to be NPP or a smaller party (37% vs. 27%).

We can also identify the new registrants who were too young to vote in 2012 but came of age by 2020. Among these youngest new voters, Republican registration is lower than among older new registrants (14% vs. 21%) while Democratic registration is higher (48% vs. 43%).

Meanwhile, some registrants have dropped off the file because they left the state, moved within the state and never re-registered, or passed away. Democrats also make up the bulk of these dropped registrants at 2.2 million (NPP/other, 1.5 million; Republicans, 1.6 million). If we subtract the number likely to have died, we can get closer to the number who left the state. The partisan split of such mortality-adjusted numbers is very similar but again tilts Democratic at 1.9 million—dropped records for both Republicans and NPP/other are at 1.4 million.

figure - New registrants favor Democrats and No Party Preference

Democrats may account for many dropped records, but California has more Democrats in the first place. Looking at the numbers as a share of all voters registered with the same party in 2012 gives a sense of the odds that someone has left the state. Seen this way, NPP/other (30%) and Republican (29%) registrants appear somewhat more likely than Democratic (27%) registrants to have moved away.

Subtracting all losses from all gains, Democrats and NPP/other each added 2.0 million registrants, while Republicans gained only 200,000—just 5% of the net increase.

Gains and losses tell only part of the story, since about 70% of registrants from 2012 never left the voter file. Most of these voters (77%) kept the same party registration, but the 2.8 million who switched produced a net loss of 48,000 for Republicans and 256,000 for NPP/other, and a net gain of 304,000 for Democrats (mostly through switches between NPP/other and Democrats).  All the same, these shifts amounted to a fraction of the changes from adding or subtracting registrants.

figure - Most party switching has occurred between Democrats and No Party Preference registrants

In sum, although it is likely that Republicans and NPP/other registrants have left the state more often than Democrats in recent years, the difference has been modest. Nor have the consequences of party switching been substantial.

The largest source of party transition in the Golden State has been new voters: both those arriving in the state and those already here who have registered to vote for the first time. These new registrants show a marked preference for No Party Preference and smaller party registration—and a slight preference for Democratic registration—over registering Republican. If these trends continue, Republican registration will continue to fall in years to come.


2024 Election elections party registration Political Landscape Population voter registration voters