The poll shows Harris at 23%, Biden at 21% and Sanders at 18%. The difference between the candidates’ numbers are within the poll’s margin of error.
Beyond the top three, Massachusetts Sen. Elizabeth Warren sits at 16%.
The race has tightened since a Quinnipiac April survey found Biden, who had not yet formally announced his candidacy, besting the other contenders with 26% of Democratic voters in the Golden State; in that poll, Sanders was at 18%, Harris 17% and Warren 7%.
Harris and Warren have both surged since that survey, while Biden has dropped and Sanders has remained steady.
The only other two candidates to reach above 1% in the poll were South Bend, Indiana, Mayor Pete Buttigieg with 3% and businessman Andrew Yang with 2%.
In the poll, Harris performs slightly better among those who identified as liberal Democrats than moderates or conservatives — 27% among very liberal and 29% for somewhat liberal, compared to 20% for moderate/conservative Democratic California voters. Biden’s numbers are much stronger among moderates/conservatives (24%) over very or somewhat liberal (16% and 17%, respectively). Sanders sees his highest numbers from among somewhat liberal Democrats (23%), while Warren is strongest with the very liberal (24%).
White Democrats were also more likely to prefer Harris (26%) or Biden (23%) than Warren (17%) or Sanders (15%). Latinos are split between Sanders (25%) and Biden (23%), while Harris (16%) and Warren (15%) garner less of their votes.
Harris performs better among California Democratic voters who said they were paying the most attention to the campaign (28%), versus those who were paying some attention (22%) or little or no attention (16%). Warren sees a similar pattern (21% of those paying a lot of attention, 11% some, 12% little/none), but Biden sees better results among those who are paying less attention (26% among little or none, 17% who are paying some or a lot). Sanders sees his highest support among those paying some attention (24%, over 16% a lot of attention, and 17% a little or none).
Biden tops other candidates in terms of who Democrats think can beat Trump (45%), over 12% for Sanders, 11% for Harris and 8% for Warren. Biden is also up front for who California Democrats said will be the best leader (26% for Biden, 18% for Harris, 17% for Sanders, and 14% for Warren), but at a smaller margin.
Biden saw a huge increase in terms of Democratic voters who think he is the best option to beat Trump (up 10 points since April), especially relative to the fact that he hasn’t seen an increase in those who plan to vote for him.
But Warren leads in terms of who Democrats in California think has the best policy ideas (28%, up from 18% in April) over Sanders (20%), Biden (11%), and Harris (9%).
Harris receives a 45% approval on her job as a US Senator for California, 34% disapprove and another 21% aren’t sure either way.
The Quinnipiac University poll was conducted from July 10 to 15 among a random sample of 1,125 California voters with a margin of error of plus or minus 3.9 percentage points, including the design effect. The survey includes 519 Democrats and Democratic leaners with a margin of error of plus or minus 5.7 percentage points, including the design effect. It is larger for subgroups.