Results of a new poll administered by CBS News/YouGov were spread on October 5. The poll asked participants from Virginia for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
In Virginia, the popular vote is usually decided by a narrow margin. This is why the state is commonly referred to as a purple state, which makes it particularly interesting from a forecasting perspective.
CBS News/YouGov poll results
According to the results, 45.0% of participants are going to vote for former Secretary of State Hillary Clinton, while 37.0% intend to vote for billionaire Donald Trump.
The poll was carried out from September 21 to September 23 among 1237 likely voters. Taking into account the poll's margin of error of +/-3.3 percentage points, the gap between both candidates is statistically significant.
Putting the results in context
As any other method, polls are subject to bias. In general, a good strategy is to not be too confident the results of an individual poll. Rather than relying on results from single polls, research in forecasting recommends to use combined polls or, even better, a combined forecast that incorporates different methods and data.
For the following analysis, we translate Clinton's and Trump's raw poll numbers into two-party vote shares. This procedure yields values of 54.9% for Clinton and 45.1% for Trump.
Results compared to other polls
Looking at an average of Virginia polls, Clinton's current two-party vote share is at 55.6%. This value is 0.7 percentage points higher than her respective numbers in the CBS News/YouGov poll. This margin is within the poll's sampling error, which suggests that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The latest PollyVote predicts Clinton to gain 50.9% of the two-party vote in Virginia. This means that Polly's forecast is 4.0 points below her polling numbers. Again, a look at the poll's error margin reveals that this deviation is significant.