NBC-WSJ-Marist released the results of a new poll, in which respondents from Pennsylvania were asked for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
NBC-WSJ-Marist poll results
Of those who responded, 48.0% said that they are going to vote for former Secretary of State Hillary Clinton, while 37.0% indicated that they would give their vote to businessman Donald Trump.
The poll was conducted from August 3 to August 7. A total of 834 registered voters responded. If one takes into account the poll's margin of error of +/-3.4 percentage points, the gap in voter support is statistically significant.
Putting the results in context
Individual polls should be interpreted with caution, because they can contain large biases. At the very least, one should check how a poll's results compare to benchmark forecasts.
For the following analysis, we translate the candidates' raw poll numbers into two-party vote shares. The respective figures are 56.5% for Clinton and 43.5% for Trump. In the most recent NBC-WSJ-Marist poll on August 20 Clinton received only 43.5%, while Trump received only 0.0%.
Comparison to other polls
Looking at an average of Pennsylvania polls, Clinton's two-party vote share is currently at 55.2%. This value is 1.3 percentage points lower than her corresponding numbers in the NBC-WSJ-Marist poll. This margin is within the poll's error margin, which means that the poll is not an outlier.
Comparison to the combined PollyVote
The most recent PollyVote forecasts Clinton to gain 54.6% of the two-party vote in Pennsylvania. That is, the combined PollyVote is 1.9 points below her polling numbers. The PollyVote forecast is therefore within the poll's sampling error.