Results of a new poll carried out by The Simon Poll/SIU were distributed. The poll asked respondents from Illinois for whom they will vote: Hillary Clinton or Donald Trump.
The Simon Poll/SIU poll results
The results show that 53.0% of participants said that they would cast a ballot for former Secretary of State Hillary Clinton, whereas 28.0% are going to vote for real estate developer 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
Single polls should be regarded with caution, since they can contain large errors. Instead of trusting the results from single polls, the best practice scientific advice is to look at combined polls or, even better, a combined forecast that includes forecasts from different methods, each of which draws upon different data.
In order to make the results comparable to forecasts from other methods, we convert them into shares of the two-party vote. This yields figures of 65.4% for Clinton and 34.6% for Trump.
Results in comparison to other polls
Clinton currently runs at 59.2% of the major two-party vote according to an average of recent polls in Illinois. This value is 6.2 percentage points lower than her respective numbers in the The Simon Poll/SIU poll. This margin is outside the poll's margin of error, which suggests that the poll is an outlier.
The poll compared with PollyVote's prediction
The most recent PollyVote forecasts 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 margin of error suggests that this difference is significant.