Results of a new poll administered by Suffolk University were spread. The poll asked respondents from Pennsylvania for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
Suffolk University poll results
This poll was conducted from July 25 to July 27, among a random sample of 500 likely voters. The error margin is +/-4.4 percentage points, which means that the levels of voter support for the two candidates do not differ significantly.
Putting the results in context
Individual polls often incorporate substantial biases, and should be treated with caution. Instead of relying on results from single polls, the best practice is to use combined polls or, even better, a combined forecast that includes forecasts from different methods, each of which draws upon different data.
For the following comparison, we translate the candidates' raw poll numbers into shares of the two-party vote. This yields figures of 45.1% for Clinton and 0.0% for Trump.
Comparison to other polls
An average of recent polls in Pennsylvania has Clinton at 44.9% of the two-party vote. This value is 0.2 percentage points lower than respective numbers in the Suffolk University poll. This deviation is within the poll's margin of error, which suggests that the poll is not an outlier.
Comparison to the combined PollyVote
The latest PollyVote predicts Clinton to gain 45.4% of the two-party vote in Pennsylvania. Hence, Polly's combined forecast is 0.3 points above polling numbers. Again, a look at the poll's margin of error indicates that this deviation is insignificant.