NBC-WSJ-Marist published the results of a new poll. In this poll, interviewees from Ohio were asked for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
In Ohio, the election outcome is often close. This is why the state is commonly referred to as a battleground state, which makes it particularly interesting from a forecasting perspective.
NBC-WSJ-Marist poll results
The results show that 43.0% of participants said that they would give their vote to former New York Senator Hillary Clinton, whereas 38.0% intend to vote for businessman Donald Trump.
The poll was conducted from August 3 to August 7 with 889 registered voters. The margin of error is +/-3.3 percentage points. This means that the levels of voter support for the Democratic and the Republican candidate do not differ significantly.
Putting the results in context
In general, however, one should not have too much faith in the results of single polls, because they sometimes contain large errors. Rather than trusting the results from single polls, forecasting research recommends to use combined polls or, even better, the combined PollyVote forecast that uses forecasts from different methods, each of which uses different data.
To make the results comparable to benchmark forecasts, we translate them into shares of the two-party vote. This procedure yields values of 53.1% for Clinton and 46.9% for Trump.
Results compared to other polls
Clinton is currently at 52.3% of the two-party vote in an average of recent polls in Ohio. Compared to her numbers in the NBC-WSJ-Marist poll Clinton's poll average is 0.8 percentage points worse. This deviation is within the poll's sampling 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. This means that the PollyVote is 1.2 points below her polling numbers. Again, a look at the poll's sampling error indicates that this deviation is insignificant.