| Results of SurveyUSA News Poll #12615 |
 | Do you approve or disapprove of the job Charles Grassley is doing as United States Senator? |
| 600 Adults | All | Gender | Race | Party Affiliation | Ideology | Abortion | Global Warming | Military Draft | Region | ||||||||||||||
| Margin of Sampling Error: ± 3.9% | Male | Female | White | Black | Hispanic | Other | Republic | Democrat | Independ | Conserva | Moderate | Liberal | Pro-life | Pro-choi | Real | Made-up | Needs | Does Not | Northeas | Southeas | Southwes | Northwes | |
| Approve | 63% | 63% | 63% | 63% | ** | ** | ** | 79% | 52% | 69% | 80% | 63% | 50% | 73% | 59% | 62% | 72% | 67% | 65% | 58% | 59% | 64% | 75% |
| Disapprove | 30% | 31% | 30% | 30% | ** | ** | ** | 15% | 43% | 23% | 17% | 28% | 43% | 21% | 33% | 31% | 22% | 28% | 28% | 30% | 37% | 30% | 24% |
| Not Sure | 7% | 6% | 8% | 7% | ** | ** | ** | 7% | 5% | 8% | 3% | 8% | 7% | 6% | 7% | 7% | 6% | 5% | 6% | 12% | 4% | 6% | 2% |
| Total | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| Composition of Adults | 100% | 48% | 52% | 94% | 2% | 2% | 2% | 32% | 37% | 27% | 26% | 45% | 18% | 42% | 54% | 71% | 24% | 24% | 72% | 40% | 20% | 21% | 19% |
 | Do you approve or disapprove of the job Tom Harkin is doing as United States Senator? |
| 600 Adults | All | Gender | Race | Party Affiliation | Ideology | Abortion | Global Warming | Military Draft | Region | ||||||||||||||
| Margin of Sampling Error: ± 4.1% | Male | Female | White | Black | Hispanic | Other | Republic | Democrat | Independ | Conserva | Moderate | Liberal | Pro-life | Pro-choi | Real | Made-up | Needs | Does Not | Northeas | Southeas | Southwes | Northwes | |
| Approve | 53% | 54% | 52% | 54% | ** | ** | ** | 33% | 72% | 56% | 30% | 59% | 70% | 42% | 63% | 63% | 30% | 53% | 54% | 51% | 56% | 48% | 59% |
| Disapprove | 40% | 39% | 41% | 39% | ** | ** | ** | 58% | 25% | 37% | 64% | 34% | 23% | 50% | 30% | 29% | 66% | 40% | 39% | 39% | 41% | 45% | 37% |
| Not Sure | 7% | 7% | 7% | 7% | ** | ** | ** | 10% | 3% | 7% | 6% | 7% | 7% | 8% | 7% | 8% | 4% | 7% | 6% | 11% | 3% | 7% | 4% |
| Total | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| Composition of Adults | 100% | 48% | 52% | 94% | 2% | 2% | 2% | 32% | 37% | 27% | 26% | 45% | 18% | 42% | 54% | 71% | 24% | 24% | 72% | 40% | 20% | 21% | 19% |