WBUR/MassINC published the results of a new poll. In this poll, participants from New Hampshire were asked for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
In New Hampshire, the popular vote is often decided by a narrow margin. This is why the state is commonly viewed as a battleground state, which makes it particularly interesting from a forecasting perspective.
WBUR/MassINC poll results
Of those who answered the question, 47.0% said that they plan to vote for former First Lady Hillary Clinton, whereas 38.0% said that they would give their vote to real estate developer Donald Trump.
The poll was conducted from September 27 to September 29 among 502 likely voters. There is a sampling error of +/-4.4 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
Individual polls should be treated with caution, since they often contain large errors. Instead of relying on results from single polls, the best practice is to rely on combined polls or, even better, the combined PollyVote forecast that draws upon forecasts from different methods, each of which draws upon different data.
In order to make the results comparable to benchmark forecasts, we convert them into shares of the two-party vote. This procedure results in figures of 55.3% for Clinton and 44.7% for Trump.
Results in comparison to other polls
An average of recent polls in New Hampshire sees Clinton at 53.9% of the two-party vote. In comparison to her numbers in the WBUR/MassINC poll Clinton's poll average is 1.4 percentage points worse. This margin is within the poll's error margin, which means that the poll is not an outlier.
Results compared to the combined PollyVote forecast
The current PollyVote expects Clinton to gain 52.9% of the two-party vote in New Hampshire. That is, Polly's combined forecast is 2.4 points below her polling numbers. The PollyVote forecast is therefore within the poll's sampling error.