NBC-WSJ-Marist released the results of a new poll, in which respondents from Ohio were asked for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
Historically, Ohio has been a purple state, in which neither the Democrats nor the Republicans have had overwhelming support to secure that state's electoral college votes. Hence, predictions in this state are of particular value.
NBC-WSJ-Marist poll results
According to the results, 43.0% of respondents are going to give their vote to former First Lady Hillary Clinton, while 38.0% plan to vote for billionaire Donald Trump.
This poll was conducted from August 3 to August 7, among a random sample of 889 registered voters. The sampling error is +/-3.3 points. This means that the levels of voter support for Trump and Clinton do not differ significantly.
Putting the results in context
Individual polls should be regarded with caution, since they often contain substantial biases. Rather than trusting the results from single polls, the recommended strategy look at combined polls or, even better, a combined forecast that relies on different methods and data.
In order to make the results comparable to benchmark forecasts, one can translate them into shares of the two-party vote. The respective figures are 53.1% for Clinton and 46.9% for Trump.
Results in comparison to other polls
If we look at an average of Ohio polls, Clinton's two-party vote share is currently at 52.2%. This value is 0.9 percentage points lower than her corresponding numbers in the NBC-WSJ-Marist poll. This difference is within the poll's margin of error, which means that the poll is not an outlier.
Comparison to the combined PollyVote
The current PollyVote anticipates Clinton to gain 51.9% of the two-party vote in Ohio. That is, the combined PollyVote is 1.2 points below her polling numbers. The PollyVote forecast is thus in line with the poll's error margin.