Results of a new poll administered by NBC-WSJ-Marist were distributed on July 14. The poll asked respondents from Ohio for whom they would vote if the Democrats nominated Hillary Clinton and the Republicans nominated Donald Trump.
Ohio is traditionally a battleground state, where the Republican and Democratic candidates have often won similar levels of voter support. Therefore, the election outcome in that state is regarded crucial in determining who will win the majority of electoral votes.
NBC-WSJ-Marist poll results
According to the results, both candidates have equal levels of support, each with 39.0% of the vote.
The poll was carried out from July 5 to July 10 among 848 registered voters. The margin of error is +/-3.4 percentage points. This means that the levels of voter support for Trump and Clinton do not differ significantly.
Putting the results in context
Single polls should be regarded with caution, since they often include large errors. At the very least, one should check how a poll's results compare to benchmark forecasts.
To make the results comparable to benchmark forecasts, we convert them into two-party vote shares. The results of the actual poll mean 50.0 % for Clinton and 50.0 % for Trump in the two-party vote share. On April 27 Clinton received 53.3% in the NBC-WSJ-Marist poll and Trump received only 46.7%.
Comparison to other polls
When compared to the average results of other polls Clinton performed worse with 0.4 percentage points, while Trump did better with 0.4 percentage points. This margin is outside the poll's margin of error, which suggests that the poll is an outlier.
The poll compared with PollyVote's prediction
The most recent PollyVote predicts Clinton to gain 50.1% and Trump 50.0% of the two-party vote in Ohio. Clinton has 0.0 percentage points less and Trump has 0.0 percentage points more when the results of the poll are compared to the combined PollyVote forecast for Ohio. Again, a look at the poll's margin of error indicates that this deviation is significant.