Quinnipiac released the results of a new poll, in which respondents from Iowa were asked for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
Historically, Iowa has been a purple state, in which neither the GOP nor the Democrats have had overwhelming support to secure its electoral college votes. This is the reason why forecasts here are of particular value.
Quinnipiac poll results
The results show that 44.0% of participants will cast a ballot for former First Lady Hillary Clinton, while 50.0% intend to vote for real estate developer Donald Trump.
This poll was conducted from September 13 to September 21, among a random sample of 612 likely voters. There is a sampling error of +/-4.0 percentage points. Considering this error margin, the race is currently a statistical tie.
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 can contain large errors. Instead of relying on results from single polls, one should consult combined polls or, even better, the combined PollyVote forecast that relies on forecasts from different methods, each of which draws upon different data.
In order to make the results comparable to benchmark forecasts, you can translate them into shares of the two-party vote. This procedure results in values of 46.8% for Clinton and 53.2% for Trump.
Results in comparison to other polls
Trump currently achieves 51.9% of the two-party vote according to an average of recent polls in Iowa. This value is 1.3 percentage points lower than her respective numbers in the Quinnipiac poll. This margin is within the poll's error margin, which means that the poll is not an outlier.
Comparison to the combined PollyVote
The current PollyVote anticipates Trump to gain 49.5% of the two-party vote in Iowa. This means that Polly's prediction is 3.7 points below her polling numbers. Again, a look at the poll's sampling error suggests that this deviation is insignificant.