NBC/WSJ/MaristNBC/WSJ/Marist released the results of a new poll, in which respondents from Florida were asked for whom they will vote: Democrat Hillary Clinton or Republican Donald Trump.
In Florida, the popular vote is usually close. This is why the state is commonly viewed as a purple state, which makes it particularly interesting from a forecasting perspective.
NBC/WSJ/MaristNBC/WSJ/Marist poll results
Of those who answered the question, 44.0% said that they intend to vote for former First Lady Hillary Clinton, while 37.0% said that they would give their vote to real estate developer Donald Trump.
The poll was in the field between July 5 and July 11. The sample size was 871 registered voters. There is a sampling error of +/-3.3 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
In general, however, don't have too much faith in the results of single polls, since they can contain large errors. Rather than trusting the results from single polls, the evidence-based approach is to use combined polls or, even better, a combined forecast that relies on different methods and data.
To make the results comparable to benchmark forecasts, you can translate them into shares of the two-party vote. This yields figures of 54.3% for Clinton and 45.7% for Trump. For comparison: Only 45.7% was obtained by Clinton in the NBC/WSJ/MaristNBC/WSJ/Marist poll on August 7, for Trump this result was only 0.0%.
Comparison to other polls
An average of recent polls in Florida sees Clinton at 51.5% of the two-party vote. This value is 2.8 percentage points lower than her corresponding numbers in the NBC/WSJ/MaristNBC/WSJ/Marist poll. This deviation is within the poll's sampling error, which suggests that the poll is not an outlier.
Comparison to the combined PollyVote
The current PollyVote forecasts Clinton to gain 50.6% of the two-party vote in Florida. That is, Polly's combined forecast is 3.7 points below her polling numbers. Again, a look at the poll's error margin shows that this deviation is significant.