Results of a new poll carried out by NBC-WSJ-Marist were spread. The poll asked interviewees from Ohio for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
In Ohio, the popular vote is usually close. This is why the state is commonly regarded as a battleground state, which makes it particularly interesting from a forecasting perspective.
NBC-WSJ-Marist poll results
Of those who responded, 43.0% said that they will vote for former First Lady Hillary Clinton, whereas 38.0% said that they would give their vote to real estate developer Donald Trump.
The poll was conducted from August 3 to August 7. A total of 889 registered voters responded. The margin of error is +/-3.3 points, which means that the poll results for Clinton and Trump do not differ significantly.
Putting the results in context
As any other method, polls are subject to bias. Therefore, as a general rule, one should not be too confident the results of an individual poll. Rather than relying on results from single polls, the best practice scientific advice is to consult combined polls or, even better, the combined PollyVote forecast that draws upon forecasts from different methods, each of which draws upon different data.
To make the results comparable to benchmark forecasts, one can translate them into shares of the two-party vote. This yields figures of 53.1% for Clinton and 46.9% for Trump.
Results in comparison to other polls
An average of recent polls in Ohio sees Clinton at 52.2% of the two-party vote. Relative to her numbers in the NBC-WSJ-Marist poll Clinton's poll average is 0.9 percentage points lower. This deviation is within the poll's margin of error, which suggests that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The latest PollyVote foresees Clinton to gain 51.9% of the two-party vote in Ohio. That is, Polly's combined forecast is 1.2 points below her polling numbers. The PollyVote forecast is thus in line with the poll's margin of error.