Monmouth 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 regarded as a battleground state, which makes it particularly interesting from a forecasting perspective.
Monmouth poll results
According to the results, 43.0% of participants indicated that they would cast a ballot for former First Lady Hillary Clinton, whereas 39.0% indicated that they would cast a ballot for businessman Donald Trump.
The poll was conducted from August 18 to August 21. A total of 402 likely voters responded. The margin of error is +/-4.9 points, which means that the levels of voter support for the two candidates do not differ significantly.
Putting the results in context
In general, however, a good strategy is to not have too much faith in the results of single polls, because they often incorporate large errors. At the very least, one should examine how a poll's results compare to benchmark forecasts.
In order to make the results comparable to forecasts from other methods, we translate them into two-party vote shares. This procedure results in figures of 52.4% for Clinton and 47.6% for Trump. On August 28 Clinton obtained only 47.6% in the Monmouth poll and Trump obtained only 0.0%.
Results vs. other polls
An average of recent polls in Ohio sees Clinton at 52.2% of the two-party vote. This value is 0.2 percentage points lower than her respective numbers in the Monmouth poll. This margin is within the poll's margin of error, which means that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The current PollyVote expects Clinton to gain 52.0% of the two-party vote in Ohio. That is, Polly's combined forecast is 0.4 points below her polling numbers. Again, a look at the poll's margin of error suggests that this difference is negligible.