Closest U.S. Senate elections in Colorado
The closest U.S. Senate election in Colorado history was in 1956, a margin of 0.44 points. John A. Carroll beat Daniel I. J. Thornton, 319,872 to 317,102. Next closest are 1942 (1.0 points) and 1972 (1.0 points).
Every state is ranked together on Closest U.S. Senate elections in history. For every Senate race Colorado has held, special elections included, see the Colorado U.S. Senate hub.
What is the closest Senate race in Colorado history?
The Colorado Senate election decided by the narrowest margin was in 1956, 0.44 points. John A. Carroll beat Daniel I. J. Thornton, 319,872 to 317,102. The next closest were 1942 (1.0 points) and 1972 (1.0 points).
How is the margin measured?
As the gap in vote share between the first and second-place finishers, from the certified general-election count. It is not adjusted for recounts, runoffs or later court rulings; the figure is the result as certified.
Does this include special elections?
No. These are the regular general elections for Colorado’s two Senate seats. Special elections to fill a vacancy appear on the Colorado Senate hub, which lists every race including specials, and in a few states one of those is closer than anything here.
Why does the list start in 1914?
Because senators were chosen by state legislatures before the Seventeenth Amendment. 1914 is the first cycle of the popular-vote era for the Senate, so it is the first Colorado election with a popular margin to measure.
| # | Election | Result | Votes | Margin |
|---|---|---|---|---|
| 1 | 1956 | John A. Carroll D def. Daniel I. J. Thornton R | 319,872 – 317,102 | 0.44 points |
| 2 | 1942 | Edward C. Johnson D def. Ralph L. Carr R | 174,612 – 170,970 | 1.0 points |
| 3 | 1972 | Floyd K. Haskell D def. Gordon Allott R | 457,545 – 447,957 | 1.0 points |
| 4 | 1914 | Charles S. Thomas D def. Hubert Work R | 102,037 – 98,728 | 1.3 points |
| 5 | 1918 | Lawrence C. Phipps R def. John F. Shafroth D | 107,726 – 104,347 | 1.6 points |
| 6 | 1986 | Timothy E. Wirth D def. Ken Kramer R | 529,449 – 512,994 | 1.5 points |
| 7 | 1980 | Gary Hart D def. Mary Estill Buchanan R | 590,501 – 571,295 | 1.6 points |
| 8 | 2010 | Michael F. Bennet D def. Ken Buck R | 851,590 – 822,731 | 1.6 points |
| 9 | 2014 | Cory Gardner R def. Mark Udall D | 983,891 – 944,203 | 1.9 points |
| 10 | 1954 | Gordon Allott R def. John A. Carroll D | 248,502 – 235,686 | 2.6 points |
| 11 | 1926 | Charles W. Waterman R def. William E. Sweet D | 149,585 – 138,113 | 3.9 points |
| 12 | 2004 | Ken Salazar D def. Pete Coors R | 1,081,188 – 980,668 | 4.8 points |
| 13 | 2002 | Wayne Allard R def. Tom Strickland D | 717,893 – 648,130 | 4.9 points |
| 14 | 2016 | Michael F. Bennet D def. Darryl Glenn R | 1,370,710 – 1,215,318 | 5.7 points |
| 15 | 1996 | Wayne Allard R def. Tom Strickland D | 750,315 – 667,600 | 5.7 points |
| 16 | 1924 | Lawrence C. Phipps R def. Alva B. Adams D | 159,698 – 139,660 | 6.3 points |
| 17 | 1932 | Alva B. Adams D def. Karl C. Schuyler R | 226,516 – 198,519 | 6.4 points |
| 18 | 1950 | Eugene D. Millikin R def. John A. Carroll D | 239,724 – 210,442 | 6.5 points |
| 19 | 1960 | Gordon Allott R def. Robert L. Knous D | 389,428 – 334,854 | 7.5 points |
| 20 | 1962 | Peter H. Dominick R def. John A. Carroll D | 328,655 – 279,586 | 8.0 points |
| 21 | 1992 | Ben Nighthorse Campbell D def. Terry Considine R | 803,725 – 662,893 | 9.1 points |
| 22 | 2020 | John W. Hickenlooper D def. Cory Gardner R | 1,731,114 – 1,429,492 | 9.3 points |
| 23 | 2008 | Mark Udall D def. Bob Schaffer R | 1,230,994 – 990,755 | 10.3 points |
| 24 | 1944 | Eugene D. Millikin R def. Barney L. Whatley D | 277,410 – 214,335 | 12.8 points |
| 25 | 1930 | Edward P. Costigan D def. George H. Shaw R | 180,028 – 137,487 | 13.2 points |