NBC-WSJ-Marist published the results of a new poll. In this poll, participants from Illinois were asked for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
NBC-WSJ-Marist poll results
The results show that 57.0% of interviewees intend to cast a ballot for former New York Senator Hillary Clinton, while 32.0% intend to vote for real estate developer Donald Trump.
The poll was conducted from March 4 to March 10. A total of 1968 registered voters responded. If one takes into account the poll's error margin of +/-2.2 percentage points, the gap in voter support is statistically significant.
Putting the results in context
Individual polls should be treated with caution, since they can incorporate large biases. Rather than relying on results from single polls, research in forecasting recommends to rely on combined polls or, even better, the combined PollyVote forecast that includes forecasts from different methods, each of which includes different data.
For the following analysis, we translate Trump's and Clinton's raw poll numbers into shares of the two-party vote. The resulting figures are 64.0% for Clinton and 36.0% for Trump.
Comparison to the combined PollyVote
The latest PollyVote anticipates Clinton to gain 58.3% of the two-party vote in Illinois. Hence, Polly's combined forecast is 5.7 points below her polling numbers. Again, a look at the poll's error margin suggests that this difference is significant.