On October 10, PPIC released the results of a new poll, in which respondents from California were asked for whom they will vote: Hillary Clinton or Donald Trump.
PPIC poll results
According to the results, 47.0% of participants would vote for former Secretary of State Hillary Clinton, whereas 31.0% plan to vote for businessman Donald Trump.
The poll was carried out between September 9 and September 18. The sample size was 1055 likely voters. There is a sampling error of +/-4.5 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
As any other method, polls are subject to bias. Hence, a good strategy is to not have too much faith in the results of a single poll. Rather than trusting the results from single polls, the recommended strategy rely on combined polls or, even better, a combined forecast that uses different methods and data.
To make the results comparable to forecasts from benchmark methods, one can convert them into two-party vote shares. This yields figures of 60.3% for Clinton and 39.7% for Trump.
Results in comparison to other polls
If we look at an average of California polls, Clinton's two-party vote share is currently at 62.0%. In comparison to her numbers in the PPIC poll Clinton's poll average is 1.7 percentage points higher. This deviation is within the poll's margin of error, which suggests that the poll is not an outlier.
Comparison to the combined PollyVote
The latest PollyVote anticipates Clinton to gain 62.3% of the two-party vote in California. That is, Polly's combined forecast is 2.0 points above her polling numbers. The PollyVote forecast is therefore in line with the poll's margin of error.