NBC-WSJ-Marist released the results of a new poll, in which respondents from California were asked for whom they will vote: Donald Trump or Hillary Clinton.
NBC-WSJ-Marist poll results
According to the results, 55.0% of participants said that they would cast a ballot for former First Lady Hillary Clinton, whereas 31.0% intend to vote for real estate developer Donald Trump.
The poll was conducted from May 29 to May 31 with 1833 likely voters. If one takes into account the poll's margin of error of +/-2.3 percentage points, the spread between both candidates is statistically significant.
Putting the results in context
In general, however, a good strategy is to not have too much faith in the results of single polls, as they often contain large errors. Rather than trusting the results from single polls, forecasting research recommends to use combined polls or, even better, a combined forecast that includes different methods and data.
For the following comparison, we convert Trump's and Clinton's raw poll numbers into shares of the two-party vote. This yields figures of 64.0% for Clinton and 36.1% for Trump.
Results in comparison to other polls
Clinton currently runs at 63.4% of the major two-party vote according to an average of recent polls in California. This value is 0.6 percentage points lower than her corresponding numbers in the NBC-WSJ-Marist poll. This margin is within the poll's margin of error, which means that the poll is not an outlier.
The poll compared with PollyVote's forecast
The current PollyVote foresees Clinton to gain 61.3% of the two-party vote in California. Hence, Polly's forecast is 2.7 points below her polling numbers. The PollyVote forecast is thus outside the poll's error margin.