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Who will win the California Democratic primary?
Starting with the Iowa caucus on February the 3rd, 2020, American voters will begin casting votes for the Democratic nominee they wish to compete President Trump. In our statistical model, we forecast which Democratic candidate will win the largest number of votes. We factor in opinion polls and betting odds in order to form a comprehensive forecast for nine of the most high-profile Democrats that have declared their candidacy for president. Our forecast automatically updates on a real-time basis as betting odds and polls change.
Last updated: Wed August 21 2019
Probability of winning largest popular vote share
Joe Biden 28.8% chance
IN PAST day week month
Bernie Sanders 20.8% chance
IN PAST day week month
Kamala Harris 20% chance
IN PAST day week month
Elizabeth Warren 13.9% chance
IN PAST day week month
Buttigieg 6% chance
O'Rourke 3.1% chance
Booker 2.5% chance
Yang 2.4% chance
Gabbard 2.4% chance
CANDIDATE
PROBABILITY OF WIN
EXPECTED WIN pct. %
WIN PROB.
2 %
8 %
24 %
49 %
83 %
% VOTE SHARE
0 %
11 %
23 %
34 %
45 %
2%
0
Joe Biden D
28.8 %
WIN CHANCE
25.2%
80% OUTCOME RANGE 11.3% TO 39.1%
2%
0
Bernie Sanders D
20.8 %
WIN CHANCE
20.9%
80% OUTCOME RANGE 7% TO 34.8%
2%
0
Kamala Harris D
20 %
WIN CHANCE
20.4%
80% OUTCOME RANGE 6.5% TO 34.3%
2%
0
Elizabeth Warren D
13.9 %
WIN CHANCE
16.4%
80% OUTCOME RANGE 2.5% TO 30.3%
2%
0
Pete Buttigieg D
6 %
WIN CHANCE
8.9%
80% OUTCOME RANGE 0% TO 22.8%
2%
0
Beto O'Rourke D
3.1 %
WIN CHANCE
3.7%
80% OUTCOME RANGE 0% TO 17.6%
2%
0
Cory Booker D
2.5 %
WIN CHANCE
1.8%
80% OUTCOME RANGE 0% TO 15.7%
2%
0
Andrew Yang D
2.4 %
WIN CHANCE
1.4%
80% OUTCOME RANGE 0% TO 15.3%
2%
0
Tulsi Gabbard D
2.4 %
WIN CHANCE
1.3%
80% OUTCOME RANGE 0% TO 15.2%
Top-two projected vote share over time
We currently estimate that Joe Biden will win the popular vote with an 4.3-point advantage over Bernie Sanders. Joe Biden has a 28.8% chance of winning the most votes in the 2020 Democratic primary and Bernie Sanders has a 20.8% chance.
67%
vote share
33 0
Current Biden polling advantage
4.3%
New Year
2020 →
20.9% Bernie Sanders 25.2% Joe Biden
Wed August 21 2019
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How accurate are our predictions early on?+
We weight candidates' vote share prediction to be 90% of opinion poll averages and 10% of betting odds in our national forecast. For our primary forecasts, we weight betting odds to be 5%. We then model the probabilities of our predictions using logistic distribution and past polling error. In early October 2015, our predictions would have shown Donald Trump winning the most votes of any GOP candidate with a 27.8% share; he ultimately won with 45.0%. Hillary Clinton was predicted to win with 62.2% of the vote and Bernie Sanders 36.4%; she ultimately won with 55.2% and he with 43.1%.

Our predictions (using data available in October 2015) of 2016 primary candidates' ultimate vote share were, on average, within 8.8 points of their actual result. Each candidate's forecast correlated with the final result by r = 84.4% and r² = 71.2%, proving predictive even in early stages of the primary process.
About this forecast
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