NBC-WSJ-Marist released the results of a new poll, in which respondents from Pennsylvania were asked for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
NBC-WSJ-Marist poll results
Of those who replied, 48.0% said that they will vote for former First Lady Hillary Clinton, whereas 37.0% revealed that they would give their vote to billionaire Donald Trump.
The poll was conducted from August 3 to August 7 with 834 registered voters. There is a sampling error of +/-3.4 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
As any other method, polls are subject to bias. Thus, as a general rule, a good strategy is to not put too much trust in the results of a single poll. Instead of relying on results from single polls, one should use combined polls or, even better, a combined forecast that draws upon different methods and data.
For the following comparison, we translate Trump's and Clinton's raw poll numbers into shares of the two-party vote. The resulting figures are 56.5% for Clinton and 43.5% for Trump.
Results vs. other polls
If we look at an average of Pennsylvania polls, Clinton's current two-party vote share is at 55.2%. Compared to her numbers in the NBC-WSJ-Marist poll Clinton's poll average is 1.3 percentage points lower. This deviation is within the poll's margin of error, which means that the poll is not an outlier.
The poll in comparison with PollyVote's prediction
The latest PollyVote foresees Clinton to gain 53.4% of the two-party vote in Pennsylvania. Hence, Polly's forecast is 3.1 points below her polling numbers. Again, a look at the poll's margin of error suggests that this deviation is insignificant.