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 County results Grassley: 50-60% 60-70% 70-80% 80-90% >90% | |||||||||||||||||
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The1998 United States Senate election in Iowa was held November 3, 1998. IncumbentRepublicanUnited States SenatorChuck Grassley sought re-election to a fourth term in theUnited States Senate, running against formerState Representative David Osterberg, who won theDemocratic nomination unopposed. Grassley had not faced a competitive election since1980; this year proved no different, and Grassley defeated Osterberg in a landslide.
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | David Osterberg | 86,064 | 99.45% | |
| Democratic | Write-ins | 476 | 0.55% | |
| Total votes | 86,540 | 100.00% | ||
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Chuck Grassley (Incumbent) | 149,943 | 99.72% | |
| Republican | Write-ins | 419 | 0.28% | |
| Total votes | 150,362 | 100.00% | ||
| No. | Date | Host | Moderator | Link | Republican | Democratic |
|---|---|---|---|---|---|---|
| Key: P Participant A Absent N Not invited I Invited W Withdrawn | ||||||
| Chuck Grassley | David Osterberg | |||||
| 1 | Oct. 19, 1998 | Iowa Public Television | Dean Borg | C-SPAN | P | P |
| Poll source | Date(s) administered | Sample size[a] | Margin of error | Chuck Grassley (R) | David Osterberg (D) | Undecided |
|---|---|---|---|---|---|---|
| Mason Dixon[2] | October 25–27, 1998 | 803 (LV) | ± 3.5% | 68% | 24% | 8% |
| Mason Dixon[2] | October 11–13, 1998 | 809 (LV) | ± 3.5% | 67% | 22% | 11% |
| Mason Dixon[2] | September 12–14, 1998 | 804 (LV) | ± 3.5% | 69% | 19% | 12% |
| Mason Dixon[2] | July 18–21, 1998 | 834 (LV) | ± 3.5% | 68% | 17% | 15% |
| Selzer & Company[2] | June 20–24, 1998 | 581 (LV) | ± 4.0% | 72% | 18% | 10% |
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Republican | Chuck Grassley (Incumbent) | 648,480 | 68.41% | −1.20% | |
| Democratic | David Osterberg | 289,049 | 30.49% | +3.29% | |
| Natural Law | Susan Marcus | 7,561 | 0.80% | −0.47% | |
| Socialist Workers | Margaret Trowe | 2,542 | 0.27% | +0.16% | |
| Write-ins | 275 | 0.03% | |||
| Majority | 359,431 | 37.92% | −4.50% | ||
| Turnout | 947,907 | ||||
| Republicanhold | Swing | ||||
