California voters face many decisions on a long and crowded June 5 primary ballot. None will be more closely watched than the choices made in the top-of-the-ticket governor’s race that will determine the top two candidates in the November election runoff. Six candidates—four Democrats and two Republicans—have been serious contenders in this race. In the May PPIC Survey, Democrat Gavin Newsom continues to lead the pack, with little separation between Republican John Cox and Democrat Antonio Villaraigosa for the coveted second-place finish. It’s a toss-up if the gubernatorial race will include two Democrats or a Democrat and a Republican. Why does this matter so much?

It is likely that a Democratic candidate will prevail—no Republican has won a statewide election since 2006. Since then, the gap in partisan registration has ballooned to 19 points (44% Democrat, 25% Republican; Secretary of State, April 2018). The issue today is turnout. The partisan makeup of this November’s electorate has consequences for the Democrats’ efforts to flip several Republican House seats in competitive California districts (Cook Report, May 10) to gain party control of the US Congress. Without a candidate at the top of the ticket, Republicans have one less reason to vote.

Californians have warmed up to the current gubernatorial contest. The May PPIC Survey finds that likely voters’ interest in news about the gubernatorial candidates has almost doubled since January (30% to 58%). Equal proportions of likely voters across parties are very or fairly closely following election news today (58% Democrats, 61% Republicans, 60% independents). Moreover, likely voters’ satisfaction with the candidate choices has grown since January (54% to 64%)—especially among Republicans, who were the least satisfied earlier this year. Majorities of likely voters across parties are now satisfied with their choices (74% Democrats, 60% Republicans, 55% independents). In addition, more likely voters have found a candidate to support for governor since January (76% to 85%), and by similarly large margins across parties (86% Democrat, 86% Republican, 81% independent) today. Democratic pluralities are favoring Newsom, Republican pluralities are supporting Cox, and independents are dividing their support across two parties and four candidates.

By contrast, we need to look no further than the US Senate primary to foreshadow the impact of a one-party governor’s contest this fall. Democratic US Senator Dianne Feinstein is on the ballot with Democratic California State Senator Kevin de León. There are no major candidates from the Republican ranks in this race. In the May PPIC Survey, likely voters’ satisfaction with senate candidate choices (50%) is much lower than in the governor’s race (64%), with vastly different satisfaction levels across parties (74% Democrat, 27% Republican, 38% independent). More importantly, fewer voters have found a candidate to support in the senate race (64%) than in the governor’s race (85%), and this trend is especially pronounced among the GOP likely voters (87% Democrats, 41% Republicans, 53% independents) today.

The top-two system was created in 2010 to encourage the growing ranks of independent voters to participate in the June primary. Third parties countered that their voters would be shut out of the November election, an outcome that has largely proven true. With the dwindling ranks of Republicans today, another flaw that impacts the two-party system has surfaced—lack of participation from those feeling unrepresented on the ballot. And with deepening partisan divisions in the country, voters cannot be counted on to cross party lines and choose a candidate from outside their ranks. Republicans face an unprecedented obstacle of unknown proportions if a one-party governor’s race depresses their turnout. In the long run, California’s democracy has a bigger problem if many voters are feeling disenfranchised by the top-two primary results and choose not to participate in a statewide election. To fully assess the significance of these issues, PPIC surveys will continue to track voter interest, candidate satisfaction, and ballot choices in this consequential election.