Poll Data For Illinois (21 Electoral Votes)
Obama : 58.7% McCain: 35.8% - Strong Obama
| Poll | Dates | Obama % | McCain % | Poll Age | Poll Weight | |||||
| Rasmussen | 500 | LV | 4.5% | 11/1 | 60 | 38 | 0 | 1 | ||
| Research 2000 | 800 | LV | 3.0% | 10/20 | - | 10/23 | 59 | 35 | 9 | 0.552 |
| University of Wisconsin | 572 | LV | 4.0% | 10/19 | - | 10/22 | 61 | 32 | 10 | 0.5 |
| Chicago Tribune | 500 | RV | 4.4% | 10/16 | - | 10/19 | 56 | 32 | 13 | 0.372 |
| Rasmussen | 500 | LV | 4.5% | 10/13 | 56 | 39 | 19 | 0.217 | ||
| Research 2000 | 800 | LV | 3.5% | 9/15 | - | 9/18 | 56 | 36 | 44 | 0.049 |
| Rasmussen | 500 | LV | 4.5% | 9/17 | 56 | 40 | 45 | 0.047 | ||
| University of Wisconsin | 600 | RV | 4.0% | 9/14 | - | 9/17 | 53 | 37 | 45 | 0.047 |
| ARG | 600 | LV | 4.0% | 9/13 | - | 9/16 | 51 | 45 | 46 | 0.045 |
| Rasmussen | 500 | LV | 4.5% | 8/12 | 55 | 40 | 81 | 0.015 | ||
| Rasmussen | 500 | LV | 4.5% | 7/8 | 50 | 37 | 116 | 0.007 | ||
| Survey USA | 603 | RV | 4.0% | 2/26 | - | 2/28 | 60 | 31 | 247 | 0.002 |
| Research 2000 | 800 | LV | 3.5% | 1/21 | - | 1/24 | 58 | 37 | 282 | 0.001 |
