NBC/WSJ/MaristNBC/WSJ 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.
Ohio is traditionally a swing state, where the Democratic and Republican candidates have often won similar levels of support among voters. This is why the election outcome in that state is viewed as important in determining which party will win the majority of electoral votes.
NBC/WSJ/MaristNBC/WSJ poll results
According to the results, 43.0% of interviewees intend to give their vote to former First Lady Hillary Clinton, while 38.0% would vote for businessman Donald Trump.
The poll was in the field between August 3 and August 7. The sample size was 889 registered voters. The sampling error is +/-3.3 percentage points, which means that the levels of voter support for Clinton and Trump do not differ significantly.
Putting the results in context
As any other method, polls are subject to bias. In general, you should not have too much confidence in the results of a single poll. Rather than trusting the results from single polls, the best practice scientific advice is to use combined polls or, even better, the combined PollyVote forecast that draws upon forecasts from different methods, each of which draws upon different data.
For the following comparison, we translate Clinton's and Trump's raw poll numbers into shares of the two-party vote. The resulting figures are 53.1% for Clinton and 46.9% for Trump. On August 9 Clinton obtained only 50.0% in the NBC/WSJ/MaristNBC/WSJ poll and Trump obtained 50.0%.
Results in comparison to other polls
If we look at an average of Ohio polls, Clinton's two-party vote share is currently at 51.5%. This value is 1.6 percentage points lower than her respective numbers in the NBC/WSJ/MaristNBC/WSJ poll. This margin is within the poll's error margin, which suggests that the poll is not an outlier.
Comparison to the combined PollyVote
The latest PollyVote predicts Clinton to gain 51.0% of the two-party vote in Ohio. That is, the PollyVote is 2.1 points below her polling numbers. The PollyVote forecast is thus within the poll's error margin.