Results of a new national poll carried out by CNN and sponsored by CNN were circulated on July 27. The poll asked respondents for whom they will vote: Democrat Hillary Clinton or Republican Donald Trump.
CNN poll results
The results show that 48.0% of interviewees would give their vote to former First Lady Hillary Clinton, while 45.0% would give their vote to businessman Donald Trump.
This poll was conducted via phone from July 22 to July 24, among a random sample of 882 participants. There is a sampling error of +/-3.5 percentage points. Considering this error margin, the race is currently a statistical tie.
Putting the results in context
As any other method, polls are subject to bias. Therefore, as a general rule, don't rely too much on the results of a single poll. At least, one should examine how a poll's results compare to benchmark forecasts.
For the following analysis, we translate the candidates' raw poll numbers into shares of the two-party vote. This procedure yields figures of 48.4% for Clinton and 51.6% for Trump. In the most recent CNN poll on July 26 Clinton received only 37.5%, while Trump received 62.5%.
Results vs. other polls
An average of recent polls has Trump at 49.5% of the two-party vote. This value is 2.1 percentage points lower than his corresponding numbers in the CNN poll. 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 expects Trump to gain 48.1% of the two-party vote. Hence, the combined PollyVote is 3.5 points below his polling numbers. Again, a look at the poll's sampling error suggests that this difference is negligible.