Results of a new poll carried out by The Simon Poll/SIU were distributed. The poll asked interviewees from Illinois for whom they will vote: Democrat Hillary Clinton or Republican Donald Trump.
The Simon Poll/SIU poll results
According to the results, 53.0% of participants will give their vote to former Secretary of State Hillary Clinton, whereas 28.0% plan to vote for billionaire Donald Trump.
The poll was conducted from September 27 to October 2. A total of 865 likely voters responded. 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
Individual polls can include substantial errors, which is why they should be interpreted with caution. Rather than relying on results from single polls, one should look at combined polls or, even better, a combined forecast that includes different methods and data.
For the following comparison, we translate Trump's and Clinton's raw poll numbers into two-party vote shares. This yields figures of 65.4% for Clinton and 34.6% for Trump.
Comparison to other polls
An average of recent polls in Illinois has Clinton at 59.2% of the two-party vote. Relative to her numbers in the The Simon Poll/SIU poll Clinton's poll average is 6.2 percentage points worse. This margin is outside the poll's margin of error, which means that the poll is an outlier.
The poll in comparison with PollyVote's forecast
The most recent PollyVote predicts Clinton to gain 59.4% of the two-party vote in Illinois. This means that the PollyVote is 6.0 points below her polling numbers. Again, a look at the poll's error margin suggests that this difference is significant.