Results of a new poll conducted by Des Moines RegisterDes Moines Register were announced. The poll asked interviewees from Iowa for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
Historically, Iowa has been a purple state, in which no single party has had overwhelming support to clinch that state's electoral college votes. This is why predictions here are of particular importance.
Des Moines RegisterDes Moines Register poll results
According to the results, 39.0% of interviewees will vote for former Secretary of State Hillary Clinton, while 43.0% plan to vote for businessman Donald Trump.
The poll was conducted from October 3 to October 6 among 642 likely voters. Considering the poll's sampling error of +/-3.9 percentage points, the results reflect a statistical tie.
Putting the results in context
Single polls should be treated with caution, since they often contain large errors. Rather, one should examine how a poll's results compare to benchmark forecasts.
For the following analysis, we translate Trump's and Clinton's raw poll numbers into two-party vote shares. The respective figures are 47.6% for Clinton and 52.4% for Trump.
Results vs. other polls
Looking at an average of Iowa polls, Trump's current two-party vote share is at 51.9%. Compared to her numbers in the Des Moines RegisterDes Moines Register poll Trump's poll average is 0.5 percentage points worse. This difference is within the poll's margin of error, which means that the poll is not an outlier.
Comparison to the combined PollyVote
The current PollyVote predicts Trump to gain 49.5% of the two-party vote in Iowa. That is, Polly's combined forecast is 2.9 points below her polling numbers. The PollyVote forecast is thus within the poll's margin of error.