Monmouth 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.
Iowa is traditionally a purple state, where the Republican and Democratic candidates have historically gained similar levels of support among voters. Therefore, the election outcome here is viewed as crucial in determining the overall result of the presidential election.
Monmouth poll results
According to the results, 37.0% of respondents would vote for former New York Senator Hillary Clinton, whereas 45.0% would vote for businessman Donald Trump.
The poll was conducted from September 12 to September 14. A total of 404 likely voters responded. Considering the poll's error margin of +/-4.9 percentage points, the results reflect a statistical tie.
Putting the results in context
As any other method, polls are subject to bias. Thus, as a general rule, you should not put too much trust in the results of a single poll. Rather, one should examine how a poll's results compare to benchmark forecasts.
For the following analysis, we convert Clinton's and Trump's raw poll numbers into two-party vote shares. This procedure results in values of 45.1% for Clinton and 54.9% for Trump.
Results in comparison to other polls
Looking at an average of Iowa polls, Trump's two-party vote share is currently at 52.8%. In comparison to his numbers in the Monmouth poll Trump's poll average is 2.1 percentage points lower. This margin is within the poll's error margin, which suggests that the poll is not an outlier.
Comparison to the combined PollyVote
The most recent PollyVote foresees Trump to gain 49.8% of the two-party vote in Iowa. Hence, the PollyVote is 5.1 points below his polling numbers. The PollyVote forecast is therefore outside the poll's margin of error.