According to our final polls-plus forecast, Donald Trump had a 62% chance of winning the Illinois primary.
Not all pollsare created equal, so our forecasts are calculated based on weighted polling averages .
The weights account for the quality of each poll based on its track record and its methodological standards. They also account for sample size and how recently it was conducted; recent polls are weighted much more heavily than older ones. Polls are also adjusted for house effects, which is a tendency to consistently show different results for a candidate than the average of other polls.
For the Illinois Republican primary, we’ve collected 11 polls. Here they are, ranked by how heavily they factor in to our latest polling averages.
• = new A = all adultsRV = registered votersLV = likely voters
| pollster | sample | weight | leader | Trump | Cruz | Kasich | Rubio | |||
|---|---|---|---|---|---|---|---|---|---|---|
| • | Mar. 9-11 | YouGov | 770 | LV | 0.67 | Trump +4 | 38% | 34% | 16% | 11% |
| • | Mar. 4-10 | Marist College | 421 | LV | 0.35 | Trump +9 | 34% | 25% | 21% | 16% |
| • | Mar. 7 | We Ask America | 1,009 | LV | 0.28 | Trump +13 | 33% | 20% | 18% | 11% |
| • | Mar. 2-6 | Research America Inc. | 600 | LV | 0.13 | Trump +10 | 32% | 22% | 18% | 21% |
| • | Feb. 24 | We Ask America | 1,311 | LV | 0.00 | Trump +17 | 38% | 16% | 9% | 21% |
| • | Feb. 15-20 | Southern Illinois U. | 306 | RV | 0.00 | Trump +13 | 28% | 15% | 13% | 14% |
| • | Dec. 20 | Compass Consulting | 2,104 | LV | 0.00 | Trump +15 | 30% | 15% | 3% | 13% |
| • | Dec. 16 | Compass Consulting | 2,104 | LV | 0.00 | Trump +15 | 31% | 16% | 3% | 13% |
| • | Aug. 16-18 | Victory Research | 801 | LV | 0.00 | Trump +6* | 23% | 4% | 2% | 5% |
| • | Jul. 20-21 | Public Policy Polling | 369 | LV | 0.00 | Walker +5* | 18% | 4% | 1% | 6% |
| • | Feb. 5 | Ogden & Fry | 971 | LV | 0.00 | Walker +19* | 8% | |||
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