Results of a new poll administered by Gravis were released. The poll asked interviewees from Pennsylvania for whom they will vote: Hillary Clinton or Donald Trump.
Gravis poll results
According to the results, 46.0% of interviewees are going to vote for former Secretary of State Hillary Clinton, whereas 43.0% intend to vote for real estate developer Donald Trump.
This poll was conducted from September 23 to September 23, among a random sample of 949 likely voters. Considering the poll's margin of error of +/-3.2 percentage points, the results reflect a statistical tie.
Putting the results in context
Single polls can include substantial errors, and should be interpreted with caution. At the very least, one should examine how a poll's results compare to benchmark forecasts.
For the following comparison, we translate Trump's and Clinton's raw poll numbers into shares of the two-party vote. This procedure results in values of 51.7% for Clinton and 48.3% for Trump. On June 28 Clinton obtained only 51.0% in the Gravis poll and Trump obtained 49.0%.
Comparison to other polls
An average of recent polls in Pennsylvania has Clinton at 51.4% of the two-party vote. This value is 0.3 percentage points lower than her corresponding numbers in the Gravis poll. This difference is within the poll's sampling error, which means that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The latest PollyVote forecasts Clinton to gain 52.5% of the two-party vote in Pennsylvania. Hence, Polly's combined forecast is 0.8 points above her polling numbers. Again, a look at the poll's sampling error shows that this deviation is negligible.