Results of a new poll carried out by NBC/WSJ/MaristNBC/WSJ 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 election outcome is usually decided by a narrow margin. This is why the state is commonly viewed as a swing state, which makes it particularly interesting from a forecasting perspective.
NBC/WSJ/MaristNBC/WSJ poll results
The poll was conducted between July 5 and July 10. The sample size was 848 registered voters. Considering the poll's sampling error of +/-3.4 percentage points, the results reflect a statistical tie.
Putting the results in context
As a general rule, however, don't have too much faith in the results of single polls, because they often incorporate large errors. At least, one should examine how a poll's results compare to benchmark forecasts.
For the following analysis, we convert the candidates' raw poll numbers into shares of the two-party vote. This procedure yields values of 50.0% for Clinton and 0.0% for Trump. On April 5 Clinton obtained 53.3% in the NBC/WSJ/MaristNBC/WSJ poll and Trump obtained 46.7%.
Comparison to other polls
When compared to the average results of other polls Clinton performed worse with 49.5 percentage points, while Trump did better with 49.5 percentage points. This margin is within the poll's error margin, which means that the poll is not an outlier. The most recent PollyVote predicts Clinton to gain 49.3% and Trump % of the two-party vote in Ohio.