Quinnipiac released the results of a new poll, in which respondents from Ohio were asked for whom they will vote: Donald Trump or Hillary Clinton.
In Ohio, the election outcome 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.
Quinnipiac poll results
According to the results, 49.0% of participants would cast a ballot for former First Lady Hillary Clinton, while 45.0% plan to vote for billionaire Donald Trump.
The poll was conducted from July 30 to August 7. A total of 812 likely voters responded. The sampling error is +/-3.4 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 should be interpreted with caution, because they may contain substantial errors. Rather, one should check how a poll's results compare to benchmark forecasts.
For the following analysis, we translate Clinton's and Trump's raw poll numbers into shares of the two-party vote. This procedure results in values of 52.1% for Clinton and 47.9% for Trump.
Comparison to other polls
If we look at an average of Ohio polls, Clinton's current two-party vote share is at 51.7%. Compared to her numbers in the Quinnipiac poll Clinton's poll average is 0.4 percentage points worse. 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 expects Clinton to gain 52.0% of the two-party vote in Ohio. That is, Polly's prediction is 0.1 points below her polling numbers. Again, a look at the poll's sampling error suggests that this difference is negligible.