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United States · Election results history · 1998 Senate · Iowa
Election 1998 Results

Each election opens in its own mode: the forecast before the votes are counted, the live count while races are still too close to call, and the results once every race is decided.

1998 US Senate election in Iowa

Charles E. Grassley (Republican) beat David Osterberg (Democrat) in Iowa in 1998, 68.4% to 30.5%, a margin of 37.9 points and 359,431 votes.

The Republican hold continued from 1992, when Chuck Grassley also won.

Republicans led in 99 of the 99 counties. The largest, Polk, cast 126,780 votes and went to the Republican by 30.3 points. The closest was Lee, where 200 votes separated the two parties.

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Early projection, based on early and incomplete polling: the likely matchups, each weighted by the betting markets' odds of both nominations, not a result. Each county is its 2024 presidential margin moved by its state's projected swing; set a national vote and every state, district and county moves by the same amount from our projection. Colours run in 100 steps from a safe Republican to a safe Democratic margin. Boundaries: US Census Bureau.

Senate

CandidatePartyVotesShare
Charles E. Grassley won Republican 648,480 68.4%
David Osterberg Democratic 289,049 30.5%
All other candidates 10,378 1.1%
Total947,907

Every county

CountyDemocratRepublicanOthersTotalMargin
Polk 43,498 34.3% 81,972 64.7% 1,310 126,780 R+30.3
Linn 22,759 34.6% 42,387 64.5% 554 65,700 R+29.9
Scott 15,244 32.7% 30,855 66.2% 475 46,574 R+33.5
Black Hawk 13,365 33.9% 25,792 65.4% 280 39,437 R+31.5
Johnson 15,138 45.1% 17,901 53.3% 530 33,569 R+8.2
Dubuque 9,824 36.0% 17,166 63.0% 263 27,253 R+26.9
Woodbury 8,079 30.5% 18,148 68.5% 272 26,499 R+38.0
Story 8,532 34.4% 16,003 64.4% 296 24,831 R+30.1
Pottawattamie 6,355 29.8% 14,601 68.6% 335 21,291 R+38.7
Cerro Gordo 5,127 31.4% 11,065 67.9% 114 16,306 R+36.4
Clinton 5,544 37.0% 9,379 62.6% 65 14,988 R+25.6
Warren 4,577 32.4% 9,414 66.7% 127 14,118 R+34.3
Marshall 4,203 30.0% 9,679 69.1% 128 14,010 R+39.1
Jasper 4,625 33.3% 9,122 65.7% 146 13,893 R+32.4
Dallas 4,057 29.7% 9,482 69.3% 142 13,681 R+39.7
Des Moines 6,047 47.4% 6,642 52.1% 71 12,760 R+4.7
Webster 3,945 31.0% 8,638 68.0% 128 12,711 R+36.9
Wapello 4,492 38.3% 7,046 60.1% 181 11,719 R+21.8
Lee 5,636 48.4% 5,836 50.1% 182 11,654 R+1.7
Muscatine 3,365 31.6% 7,175 67.3% 118 10,658 R+35.7
Sioux 880 8.9% 9,017 90.9% 26 9,923 R+82.0
Marion 2,737 27.7% 7,107 71.9% 44 9,888 R+44.2
Boone 2,915 32.6% 5,927 66.3% 98 8,940 R+33.7
Benton 2,438 28.0% 6,200 71.2% 66 8,704 R+43.2
Bremer 1,787 21.8% 6,375 77.6% 52 8,214 R+55.9
Fayette 1,894 25.3% 5,520 73.8% 65 7,479 R+48.5
Buchanan 2,008 27.5% 5,228 71.5% 79 7,315 R+44.0
Carroll 1,785 25.2% 5,243 73.9% 67 7,095 R+48.7
Henry 2,009 28.4% 4,991 70.5% 84 7,084 R+42.1
Mahaska 1,449 20.9% 5,443 78.4% 55 6,947 R+57.5
Jones 1,739 25.4% 5,038 73.6% 72 6,849 R+48.2
Hardin 1,621 23.8% 5,151 75.6% 42 6,814 R+51.8
Washington 1,754 25.9% 4,946 72.9% 85 6,785 R+47.0
Winneshiek 1,730 25.6% 4,967 73.5% 58 6,755 R+47.9
Plymouth 1,245 18.5% 5,461 81.2% 20 6,726 R+62.7
Kossuth 1,713 25.7% 4,894 73.3% 66 6,673 R+47.7
Tama 1,689 26.2% 4,697 72.9% 58 6,444 R+46.7
Clayton 1,658 25.8% 4,724 73.6% 39 6,421 R+47.7
Poweshiek 1,983 31.0% 4,324 67.6% 94 6,401 R+36.6
Jefferson 1,354 21.2% 3,763 59.0% 1,256 6,373 R+37.8
Jackson 1,946 30.8% 4,330 68.5% 49 6,325 R+37.7
Cedar 1,812 29.6% 4,254 69.5% 59 6,125 R+39.9
Dickinson 1,675 28.1% 4,220 70.8% 67 5,962 R+42.7
Delaware 1,377 23.2% 4,537 76.3% 30 5,944 R+53.2
Floyd 1,423 24.0% 4,452 75.0% 63 5,938 R+51.0
Clay 1,490 25.6% 4,306 73.9% 33 5,829 R+48.3
Iowa 1,363 23.6% 4,339 75.3% 62 5,764 R+51.6
Hamilton 1,516 26.5% 4,165 72.7% 47 5,728 R+46.2
Buena Vista 1,286 23.0% 4,266 76.3% 39 5,591 R+53.3
Page 917 17.0% 4,417 81.9% 59 5,393 R+64.9
Chickasaw 1,159 21.5% 4,175 77.6% 46 5,380 R+56.1
Madison 1,498 27.9% 3,794 70.6% 82 5,374 R+42.7
Butler 959 19.2% 4,007 80.1% 37 5,003 R+60.9
Cass 998 20.1% 3,926 78.9% 49 4,973 R+58.9
Crawford 1,143 23.4% 3,723 76.1% 27 4,893 R+52.7
O'Brien 828 17.1% 3,998 82.4% 27 4,853 R+65.3
Grundy 779 16.3% 4,000 83.5% 13 4,792 R+67.2
Cherokee 1,113 23.7% 3,542 75.3% 46 4,701 R+51.7
Allamakee 1,201 25.8% 3,395 73.0% 53 4,649 R+47.2
Wright 1,190 26.4% 3,316 73.5% 8 4,514 R+47.1
Harrison 1,161 26.2% 3,186 72.0% 78 4,425 R+45.8
Union 1,144 26.1% 3,204 73.2% 32 4,380 R+47.0
Sac 859 19.8% 3,454 79.5% 34 4,347 R+59.7
Guthrie 1,152 26.7% 3,113 72.2% 44 4,309 R+45.5
Mitchell 1,044 24.4% 3,198 74.8% 35 4,277 R+50.4
Shelby 994 23.4% 3,225 76.1% 20 4,239 R+52.6
Hancock 896 21.5% 3,237 77.8% 29 4,162 R+56.2
Winnebago 1,001 24.2% 3,103 74.9% 40 4,144 R+50.7
Montgomery 726 18.0% 3,251 80.8% 49 4,026 R+62.7
Appanoose 1,197 30.2% 2,733 68.9% 36 3,966 R+38.7
Lyon 554 14.2% 3,313 85.0% 29 3,896 R+70.8
Franklin 722 18.6% 3,129 80.7% 26 3,877 R+62.1
Calhoun 845 21.8% 2,989 77.2% 36 3,870 R+55.4
Greene 1,053 27.2% 2,771 71.7% 42 3,866 R+44.4
Humboldt 724 19.0% 3,057 80.1% 35 3,816 R+61.1
Mills 805 21.4% 2,909 77.2% 52 3,766 R+55.9
Keokuk 907 24.1% 2,824 75.0% 34 3,765 R+50.9
Howard 901 24.4% 2,749 74.5% 41 3,691 R+50.1
Monona 947 26.4% 2,590 72.2% 52 3,589 R+45.8
Palo Alto 1,141 31.9% 2,419 67.6% 16 3,576 R+35.7
Clarke 1,004 28.9% 2,412 69.5% 56 3,472 R+40.6
Emmet 1,118 32.5% 2,290 66.6% 30 3,438 R+34.1
Adair 715 21.0% 2,665 78.1% 32 3,412 R+57.2
Decatur 827 24.3% 2,538 74.6% 37 3,402 R+50.3
Louisa 1,010 29.8% 2,336 69.0% 41 3,387 R+39.1
Worth 841 26.1% 2,341 72.6% 42 3,224 R+46.5
Lucas 769 25.3% 2,250 74.1% 19 3,038 R+48.7
Pocahontas 672 23.0% 2,225 76.0% 31 2,928 R+53.0
Davis 855 29.4% 2,014 69.2% 40 2,909 R+39.8
Ida 512 17.8% 2,346 81.4% 24 2,882 R+63.6
Van Buren 762 26.9% 2,036 71.8% 39 2,837 R+44.9
Monroe 820 29.2% 1,952 69.5% 38 2,810 R+40.3
Fremont 633 24.1% 1,957 74.6% 32 2,622 R+50.5
Audubon 726 28.8% 1,788 70.8% 11 2,525 R+42.1
Taylor 570 23.3% 1,847 75.4% 33 2,450 R+52.1
Wayne 697 29.1% 1,697 70.8% 2 2,396 R+41.7
Ringgold 507 21.9% 1,789 77.1% 24 2,320 R+55.3
Osceola 359 16.4% 1,810 82.5% 24 2,193 R+66.2
Adams 406 24.1% 1,252 74.4% 24 1,682 R+50.3

Margin: the Democrat's share of all votes minus the Republican's. Sources and how the results were checked.

Iowa Senate elections we hold

YearWinnerMargin
2022 Chuck Grassley (R) R+12.2
2020 Joni Ernst (R) R+6.6
2016 Chuck Grassley (R) R+24.4
2014 Joni Ernst (R) R+8.3
2010 Chuck Grassley (R) R+31.0
2008 Tom Harkin (D) D+25.4
2004 Charles E. Grassley (R) R+42.3
2002 Tom Harkin (D) D+10.4
1998 Charles E. Grassley (R) R+37.9
1996 Tom Harkin (D) D+5.1
1992 Chuck Grassley (R) R+42.4
1990 Tom Harkin (D) D+9.1
1986 Charles E. Grassley (R) R+32.5
1984 Tom Harkin (D) D+11.8
1980 Charles E. Grassley (R) R+7.9
1978 Roger W. Jepsen (R) R+3.2
1974 John C. Culver (D) D+4.8
1972 Dick Clark (D) D+11.0
1968 Harold E. Hughes (D) D+0.6
1966 Jack Miller (R) R+23.1
1962 Bourke Hickenlooper (R) R+6.8
1960 Jack Miller (R) R+3.8
1956 Bourke Hickenlooper (R) R+7.8
1954 Thomas E. Martin (R) R+4.7
1950 Bourke Hickenlooper (R) R+10.1
1948 Guy M. Gillette (D) D+16.2
1944 Bourke Hickenlooper (R) R+2.9
1942 George A. Wilson (R) R+16.3
1938 Guy M. Gillette (D) D+0.3
1936 Clyde L. Herring (D) D+3.4
1932 Richard L. Murphy (D) D+13.9
1930 Lester Dickinson (R) R+13.3
1926 Smith W. Brookhart (R) R+13.2
1924 Smith W. Brookhart (R) R+0.1
1920 Albert B. Cummins (R) R+24.0
1918 William S. Kenyon (R) R+30.8
1914 Albert B. Cummins (R) R+9.0