On October 23, NBC-WSJ-Marist released the results of a new poll, in which respondents from Arizona were asked for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
NBC-WSJ-Marist poll results
Of those who responded, 41.0% said that they will vote for former Secretary of State Hillary Clinton, whereas 42.0% said that they would give their vote to businessman Donald Trump.
The poll was conducted from September 6 to September 8 among 649 likely voters. There is a sampling error of +/-3.8 percentage points. Considering this error margin, the race is currently a statistical tie.
Putting the results in context
Individual polls should be regarded with caution, since they often include large biases. Instead of trusting the results from single polls, forecasting research recommends to look at combined polls or, even better, a combined forecast that draws upon different methods and data.
In order to make the results comparable to forecasts from other methods, you can translate them into two-party vote shares. This procedure results in figures of 49.4% for Clinton and 50.6% for Trump.
Results in comparison to other polls
An average of recent polls in Arizona has Trump at 49.1% of the two-party vote. This value is 1.5 percentage points lower than his respective numbers in the NBC-WSJ-Marist poll. This deviation is within the poll's sampling error, which means that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The current PollyVote forecasts Trump to gain 52.0% of the two-party vote in Arizona. This means that the combined PollyVote is 1.4 points above his polling numbers. The PollyVote forecast is therefore in line with the poll's error margin.