The rise of independent voter registration has been one of the most persistent voting trends in California—and the US. In 1962, just 3% of Californians registered as independent—officially known as “Decline to State”; by the eve of the 2018 election, what are now called “No Party Preference” (NPP) voters outnumbered Republicans. Many have interpreted this remarkable trend as a rejection of the major parties. It has helped motivate electoral changes from redistricting reform to open primaries. But a funny thing happened on the way to independent dominance: since 2018, the overall share of NPP voters has undergone the sharpest reversal in 60 years of registration data.

This about-face has been especially visible among the youngest registrants. In just two election cycles, the independent registration rate among voters under 25 has fallen to levels unseen in almost two decades. Democratic registration has benefited most from this change, but Republican registration is also modestly higher, and the party has made its most sustained gains among young voters since at least 2002.

This reversal is also marked among Latinos and Asian Americans. And significant shares of both groups have registered as Republicans, even as Republican registration continued to slide among all other Californians.

California’s version of automatic voter registration (AVR) is playing a big role in this shift. AVR actively promotes registration for those applying for or renewing a driver’s license or state ID at the Department of Motor Vehicles. This has boosted not only new registrations and address updates, but also refreshed records among those who haven’t moved or changed their names. The numbers are staggering. Three-quarters of voters either created or updated registration records since the advent of AVR in April 2018, compared to just 41% in the four years between 2012 and 2016. Virtually all this increase is due to AVR, which is now the touch point for 35% of the records in the file.

AVR registrants have been notably less likely to be independent (16%) than voters who create or update records some other way (24%) or do not make any changes (23%). The differences are even larger among younger registrants. However, AVR isn’t the only factor in the rise and fall of independent registration. Voters creating or updating records outside of AVR used to push independent registration higher; now they are maintaining the status quo.

Polarization may also be driving some of this trend. In 2010, 49% of major party identifiers in the PPIC Statewide Survey had a favorable view of their own party and an unfavorable view of the opposition; by 2022, that share had climbed to 59%. Those who lean toward one party but might once have called themselves independent may be finding it harder to avoid taking sides.

But AVR registrants are especially sour on choosing “no party preference.” These voters might just be more inclined to join a political party, but there could be a more technical explanation. Initially, AVR’s electronic interface unintentionally steered users toward NPP registration, and NPP numbers surged until the interface was revised to address the issue. Now, the electronic interface for AVR registration places “No Party/None” at the bottom of a long list of party choices, along with a prompt at the top instructing users to “select a political party preference below.” This may subtly push users toward choosing a party while downplaying “no party” as an option.

There are probably a number of explanations for the fact that independent registration is no longer the juggernaut it once was. While it seems clear that decisions about party registration can be swayed by the way registration forms are set up, it’s also possible that many Californians are changing their minds about joining political parties. Independent registration won’t disappear, but party registration is likely to continue surging in the near future.