a recent PPIC poll on the June 2018 primary in California which demonstrates the current state of play in the race for governor (which is open due to term limits preventing 4-term Governor Jerry Brown from appearing on the ballot again) as well as the race for the United States Senate seat currently held by Diane Feinstein.
As in every public poll that has been released testing the California governor's race, Lieutenant Governor (and former San Francisco Mayor) Gavin Newsom is in the lead, with 23 percentage of respondents expressing a preference for him while former Los Angeles Mayor (and former California Assembly Speaker) Antonio Villaraigosa relatively close behind at 18 and State Treasurer and State Controller John Chiang far behind at 9 tied with the highest Republican contender John Cox. In June 2018 all gubernatorial candidates will appear on one ballot and the Top 2, regardless of party will advance to the November 2018 ballot.
In the Senate race it appears as if Senator Feinstein is well ahead of her challenger, State Senate head Kevin de León since she leads by a massive 45% to 21% with "Don't Know" at 33%.
However, as most political pundits know anytime an incumbent (especially one who has been in office since 1994(!)) is below 50%, they should be nervous. That being said it is very likely that again that the two top candidates will now will be the two top candidates in June and thus these races could last until November 2018. This is one of the main problems with state's Top 2 primary (which was put into place by a ballot measure championed by "centrist Republican" Abel Maldonado during the Schwarzenegger era of California politics in 2004). It's very possible California voters will have a chance to repeal the Top 2 Primary system in a November 2018 ballot measure.