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United States · Election results history · 1966 Senate · Illinois
Election 1966 Results

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1966 US Senate election in Illinois

Charles H. Percy (Republican) beat Paul H. Douglas (Democrat) in Illinois in 1966, 54.9% to 43.9%, a margin of 11.0 points and 422,302 votes.

Illinois changed party: in 1960 it went Democratic, for Paul H. Douglas.

Republicans led in 93 of the 102 counties as they stood then and Democrats in 9. The largest, Cook, cast 2,002,178 votes and went to the Republican by 4.1 points. The closest was Brown, where 76 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 H. Percy won Republican 2,100,449 54.9%
Paul H. Douglas Democratic 1,678,147 43.9%
All other candidates 44,129 1.2%
Total3,822,725

Every county

CountyDemocratRepublicanOthersTotalMargin
Cook 944,538 47.2% 1,026,012 51.2% 31,628 2,002,178 R+4.1
Du Page 32,513 23.7% 104,783 76.3% 137,296 R+52.6
Lake 26,627 29.4% 56,219 62.1% 7,696 90,542 R+32.7
Will 31,508 43.3% 40,189 55.2% 1,142 72,839 R+11.9
St. Clair 38,937 54.6% 32,375 45.4% 13 71,325 D+9.2
Madison 36,495 52.6% 32,745 47.2% 159 69,399 D+5.4
Kane 21,202 31.7% 45,778 68.3% 66,980 R+36.7
Winnebago 24,990 38.7% 38,631 59.9% 887 64,508 R+21.1
Sangamon 28,139 44.6% 34,381 54.5% 529 63,049 R+9.9
Peoria 23,925 43.2% 31,253 56.4% 218 55,396 R+13.2
Rock Island 24,258 48.7% 25,550 51.3% 49,808 R+2.6
La Salle 17,704 42.5% 23,815 57.2% 89 41,608 R+14.7
Macon 20,906 50.5% 20,455 49.5% 41,361 D+1.1
Tazewell 16,957 47.2% 18,962 52.8% 35,919 R+5.6
Vermilion 15,512 44.5% 19,366 55.5% 34,878 R+11.0
Champaign 12,453 35.9% 21,825 63.0% 384 34,662 R+27.0
McHenry 8,971 27.2% 24,028 72.8% 32,999 R+45.6
McLean 10,139 33.1% 20,360 66.5% 102 30,601 R+33.4
Kankakee 11,953 39.4% 18,133 59.8% 225 30,311 R+20.4
Adams 11,652 43.9% 14,804 55.7% 104 26,560 R+11.9
Knox 10,584 44.6% 13,118 55.2% 49 23,751 R+10.7
Williamson 9,658 46.3% 11,190 53.7% 20,848 R+7.3
Macoupin 10,647 51.8% 9,871 48.0% 40 20,558 D+3.8
Whiteside 6,505 33.0% 13,198 67.0% 19,703 R+34.0
Fulton 8,863 48.2% 9,534 51.8% 18,397 R+3.6
Franklin 9,855 54.2% 8,318 45.8% 18,173 D+8.5
Henry 7,137 40.0% 10,704 60.0% 17,841 R+20.0
De Kalb 5,053 28.3% 12,726 71.3% 58 17,837 R+43.0
Coles 7,401 44.0% 9,321 55.4% 93 16,815 R+11.4
Marion 7,768 47.4% 8,634 52.6% 16,402 R+5.3
Jackson 7,966 49.0% 8,280 51.0% 16,246 R+1.9
Christian 8,340 54.6% 6,927 45.4% 15,267 D+9.3
Bureau 5,476 36.5% 9,520 63.5% 14,996 R+27.0
Stephenson 5,201 34.7% 9,774 65.3% 14,975 R+30.5
Livingston 4,055 27.1% 10,912 72.9% 14,967 R+45.8
Montgomery 7,336 49.6% 7,455 50.4% 14,791 R+0.8
Morgan 5,883 41.7% 8,239 58.3% 14,122 R+16.7
Randolph 6,180 45.2% 7,489 54.8% 13,669 R+9.6
Jefferson 6,347 46.8% 7,205 53.2% 13,552 R+6.3
Ogle 3,414 25.4% 9,956 74.0% 84 13,454 R+48.6
Iroquois 3,645 28.1% 9,269 71.4% 68 12,982 R+43.3
Logan 5,214 41.3% 7,416 58.7% 12,630 R+17.4
Lee 4,168 33.6% 8,198 66.1% 37 12,403 R+32.5
Saline 5,541 46.3% 6,437 53.7% 11,978 R+7.5
Woodford 3,734 34.5% 7,101 65.5% 10,835 R+31.1
Clinton 4,634 43.4% 6,035 56.6% 10,669 R+13.1
Effingham 4,439 42.3% 5,984 57.0% 77 10,500 R+14.7
McDonough 3,332 31.8% 7,131 68.0% 29 10,492 R+36.2
Edgar 3,961 38.4% 6,253 60.6% 111 10,325 R+22.2
Perry 4,647 46.5% 5,355 53.5% 10,002 R+7.1
Shelby 4,723 48.1% 5,098 51.9% 9,821 R+3.8
Hancock 3,790 38.9% 5,934 60.9% 19 9,743 R+22.0
Fayette 4,319 45.5% 5,172 54.5% 9,491 R+9.0
Grundy 2,942 33.0% 5,940 66.6% 32 8,914 R+33.6
Pike 4,339 49.3% 4,461 50.7% 2 8,802 R+1.4
White 3,852 44.1% 4,882 55.9% 1 8,735 R+11.8
Wayne 3,236 37.6% 5,365 62.4% 8,601 R+24.8
Warren 3,047 36.0% 5,386 63.7% 20 8,453 R+27.7
Crawford 3,364 40.0% 5,056 60.0% 8,420 R+20.1
Monroe 3,107 38.8% 4,907 61.2% 8,014 R+22.5
Mercer 3,063 39.6% 4,665 60.2% 16 7,744 R+20.7
Clark 3,168 41.0% 4,550 59.0% 7,718 R+17.9
Douglas 2,943 39.0% 4,574 60.6% 35 7,552 R+21.6
Clay 3,259 43.5% 4,230 56.5% 7,489 R+13.0
Kendall 1,756 24.0% 5,565 76.0% 7,321 R+52.0
Jo Daviess 2,576 35.2% 4,740 64.8% 7,316 R+29.6
Lawrence 2,963 40.6% 4,330 59.4% 7,293 R+18.7
Richland 2,774 38.4% 4,425 61.3% 16 7,215 R+22.9
Union 3,721 52.1% 3,424 47.9% 7,145 D+4.2
De Witt 2,875 41.2% 4,062 58.2% 40 6,977 R+17.0
Jersey 3,383 48.8% 3,554 51.2% 6,937 R+2.5
Boone 1,990 29.0% 4,865 70.8% 18 6,873 R+41.8
Washington 2,375 34.6% 4,491 65.4% 6,866 R+30.8
Mason 3,161 46.2% 3,681 53.8% 4 6,846 R+7.6
Ford 2,157 31.6% 4,677 68.4% 6,834 R+36.9
Carroll 2,084 31.0% 4,641 69.0% 6,725 R+38.0
Alexander 3,244 49.2% 3,347 50.8% 6,591 R+1.6
Greene 3,007 46.2% 3,497 53.8% 6,504 R+7.5
Cass 3,143 48.7% 3,311 51.3% 6,454 R+2.6
Bond 2,771 44.4% 3,466 55.6% 6,237 R+11.1
Piatt 2,263 37.9% 3,657 61.2% 55 5,975 R+23.3
Massac 2,248 39.0% 3,513 60.9% 7 5,768 R+21.9
Wabash 2,239 38.8% 3,519 61.1% 6 5,764 R+22.2
Marshall 2,283 40.6% 3,334 59.4% 5,617 R+18.7
Jasper 2,381 44.6% 2,940 55.0% 22 5,343 R+10.5
Moultrie 2,368 45.0% 2,900 55.0% 5,268 R+10.1
Hamilton 2,129 41.6% 2,985 58.4% 5,114 R+16.7
Cumberland 2,253 46.1% 2,633 53.9% 4,886 R+7.8
Menard 1,904 41.4% 2,686 58.4% 7 4,597 R+17.0
Schuyler 1,736 39.8% 2,625 60.2% 4,361 R+20.4
Pulaski 2,059 47.6% 2,264 52.4% 4,323 R+4.7
Gallatin 2,006 51.9% 1,859 48.1% 3,865 D+3.8
Edwards 1,269 33.6% 2,509 66.4% 3,778 R+32.8
Henderson 1,501 40.6% 2,193 59.4% 3,694 R+18.7
Johnson 1,256 35.8% 2,250 64.2% 3,506 R+28.4
Scott 1,490 44.0% 1,894 55.9% 2 3,386 R+11.9
Stark 1,164 37.3% 1,958 62.7% 3,122 R+25.4
Brown 1,574 51.2% 1,498 48.8% 3,072 D+2.5
Calhoun 1,440 47.5% 1,592 52.5% 1 3,033 R+5.0
Hardin 1,290 46.5% 1,487 53.5% 2,777 R+7.1
Putnam 987 43.5% 1,280 56.4% 4 2,271 R+12.9
Pope 812 37.3% 1,363 62.7% 2,175 R+25.3

Counties as they stood in 1966; some have since been split, merged or renamed. Margin: the Democrat's share of all votes minus the Republican's. Sources and how the results were checked.

Illinois Senate elections we hold

YearWinnerMargin
2022 Tammy Duckworth (D) D+15.3
2020 Richard J Durbin (D) D+16.0
2016 Tammy Duckworth (D) D+15.1
2014 Dick Durbin (D) D+10.9
2010 Mark Kirk (R) R+1.6
2008 Richard J. Durbin (D) D+39.3
2004 Barack Obama (D) D+42.9
2002 Richard J. Durbin (D) D+22.3
1998 Peter G. Fitzgerald (R) R+2.9
1996 Richard J. Durbin (D) D+15.4
1992 Carol Moseley-Braun (D) D+10.2
1990 Paul Simon (D) D+30.1
1986 Alan J. Dixon (D) D+31.4
1984 Paul Simon (D) D+1.9
1980 Alan J. Dixon (D) D+13.5
1978 Charles H. Percy (R) R+7.9
1974 Adlai Stevenson III (D) D+24.9
1972 Charles H. Percy (R) R+24.9
1968 Everett Dirksen (R) R+6.4
1966 Charles H. Percy (R) R+11.0
1962 Everett Dirksen (R) R+5.7
1960 Paul H. Douglas (D) D+9.4
1956 Everett Dirksen (R) R+8.4
1954 Paul H. Douglas (D) D+7.1
1950 Everett Dirksen (R) R+8.1
1948 Paul H. Douglas (D) D+10.5
1944 Scott W. Lucas (D) D+5.6
1942 C. Wayland Brooks (R) R+6.8
1938 Scott W. Lucas (D) D+3.0
1936 James H. Lewis (D) D+15.8
1932 William H. Dieterich (D) D+6.2
1930 James H. Lewis (D) D+33.3
1926 Frank L. Smith (R) R+3.7
1924 Charles S. Deneen (R) R+28.2
1920 William B. McKinley (R) R+40.0
1918 Medill McCormick (R) R+5.6
1914 Lawrence Y. Sherman (R) R+1.7