On October 8, Gravis released the results of a new poll, in which respondents from South Carolina were asked for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
Gravis poll results
Of those who answered the question, 42.0% said that they would vote for former First Lady Hillary Clinton, while 46.0% revealed that they would give their vote to businessman Donald Trump.
This poll was conducted from August 15 to August 17, among a random sample of 768 registered voters. There is a sampling error of +/-3.5 percentage points. Considering this error margin, the race is currently a statistical tie.
Putting the results in context
As any other method, polls are subject to bias. Thus, as a general rule, one should not be too confident the results of an individual poll. Rather than relying on results from single polls, forecasting research recommends to consult combined polls or, even better, the combined PollyVote forecast that incorporates different methods and data.
For the following comparison, we translate Clinton's and Trump's raw poll numbers into two-party vote shares. The respective figures are 47.7% for Clinton and 52.3% for Trump.
Results in comparison to other polls
An average of recent polls in South Carolina sees Trump at 54.5% of the two-party vote. Compared to his numbers in the Gravis poll Trump's poll average is 2.2 percentage points better. This deviation is within the poll's sampling error, which suggests that the poll is not an outlier.
The poll in comparison with PollyVote's forecast
The latest PollyVote expects Trump to gain 55.4% of the two-party vote in South Carolina. That is, Polly's forecast is 3.1 points above his polling numbers. The PollyVote forecast is therefore in line with the poll's margin of error.