The 2020 United States Senate election in South Dakota was held on November 3, 2020, to elect a member of the United States Senate to represent the State of South Dakota, concurrently with the 2020 U.S. presidential election, as well as other elections to the United States Senate, elections to the United States House of Representatives and various state and local elections. Incumbent Republican Senator Mike Rounds was reelected to a second term in office, overperforming Donald Trump in the concurrent presidential election by 5.32 points.

Republican primary Candidates Nominee Mike Rounds, incumbent U.S. senatorRounds, Johnson gearing up for 2020

Eliminated in primary Scyller Borglum, state representative

Results

Democratic primary Candidates

Nominee Daniel Ahlers, former state representative and former state senator

Did not qualify Clara Hart, board member of the Sioux Falls Arts Council

Declined Erin Healy, state representative Brendan Johnson, former United States Attorney for the District of South Dakota Billie Sutton, former minority leader of the South Dakota Senate and nominee for Governor of South Dakota in 2018 Susan Wismer, state senator and Democratic nominee for Governor of South Dakota in 2014

Independents Candidates Withdrew Clayton Walker, independent candidate in the 2014 United States Senate election in South Dakota and Democratic candidate in the 2010 South Dakota House of Representatives elections

General election Predictions SourceRankingAs of The Cook Political Report October 29, 2020 Inside Elections October 28, 2020 Sabato's Crystal Ball November 2, 2020Daily Kos October 30, 2020PoliticoNovember 2, 2020RCPOctober 23, 2020DDHQNovember 3, 2020538November 2, 2020EconomistNovember 2, 2020

Polling Poll source Date(s)administered Samplesize Marginof errorMikeRounds (R)DanAhlers (D) Undecided Nielson Brothers PollingNielson Brothers PollingOctober 24–28, 2020479 (LV)± 4.48%56%39%5%

Results

By county CountyMike RoundsRepublicanDaniel AhlersDemocraticMarginTotalvotes#%#%#%Aurora1,00271.3240328.6859942.631,405Beadle5,10471.991,98628.013,11843.987,090Bennett72962.5243737.4829225.041,166Bon Homme2,15672.1183427.891,32244.212,990Brookings8,79260.485,74639.523,04620.9514,538Brown11,16864.006,28336.004,88527.9917,451Brule1,73569.6575630.3597939.302,491Buffalo22340.9232259.08-99-18.17545Butte3,80979.8596120.152,84859.714,770Campbell74585.9312214.0762371.86867Charles Mix2,54266.881,25933.121,28333.753,801Clark1,39775.6445024.3694751.271,847Clay2,85750.442,80749.56500.885,664Codington9,47972.333,62627.675,85344.6613,105Corson68153.8858346.12987.751,264Custer3,97372.821,48327.182,49045.645,456Davison5,89369.882,54030.123,35339.768,433Day1,89563.931,06936.0782627.872,964Deuel1,71473.1962826.811,08646.372,342Dewey88445.431,06254.57-178-9.151,946Douglas1,46986.2123513.791,23472.421,704Edmunds1,53977.4544822.551,09154.911,987Fall River3,00975.1999324.812,01650.374,002Faulk97582.0721317.9376264.141,188Grant2,72372.631,02627.371,69745.273,749Gregory1,76678.3548821.651,27856.702,254Haakon1,03290.691069.3192681.371,138Hamlin2,41378.6065721.401,75657.203,070Hand1,48079.6637820.341,10259.311,858Hanson1,79676.1056423.901,23252.202,360Harding72790.88739.1365481.75800Hughes6,21770.952,54629.053,67141.898,763Hutchinson2,98279.4477220.562,21058.873,754Hyde56879.8914320.1142559.77711Jackson75667.9235732.0839935.851,113Jerauld72072.2227727.7844344.43997Jones49783.399916.6139866.78596Kingsbury1,97070.8980929.111,16141.782,779Lake3,81664.842,06935.161,74729.695,885Lawrence9,38568.294,35831.715,02736.5813,743Lincoln21,22165.8311,01334.1710,20831.6732,234Lyman1,06666.6753333.3353333.331,599Marshall1,33461.0085339.0048121.992,187McCook2,07271.2883528.721,23742.552,907McPherson1,08682.2123517.7985164.421,321Meade10,35576.533,17623.477,17953.0613,531Mellette46860.7030339.3016521.40771Miner80770.4233929.5846840.841,146Minnehaha52,77357.6338,79942.3713,97415.2691,572Moody1,87758.291,34341.7153416.583,220Oglala Lakota51015.932,69184.07-2,181-68.133,201Pennington37,69466.2719,18433.7318,51032.5456,878Perkins1,39584.8524915.151,14669.711,644Potter1,16083.8222416.1893667.631,384Roberts2,52958.871,76741.1376217.744,296Sanborn89876.1728123.8361752.331,179Spink2,17868.8498631.161,19237.673,164Stanley1,27477.1237822.8889654.241,652Sully75981.8816818.1259163.75927Todd70628.221,79671.78-1,090-43.572,502Tripp2,18881.3450218.661,68662.682,690Turner3,41675.211,12624.792,29050.424,542Union6,36472.562,40727.443,95745.118,771Walworth2,04079.5352520.471,51559.062,565Yankton6,99464.513,84835.493,14629.0210,842Ziebach45049.5645850.44-8-0.88908 Totals276,23265.74143,98734.26132,24531.47420,219

Counties that flipped from Democratic to Republican Clay (largest municipality: Vermillion) Day (largest municipality: Webster) Marshall (largest municipality: Britton) Mellette (largest municipality: White River) Roberts (largest municipality: Sisseton)

Notes

References

External links

(State affiliate of the U.S. League of Women Voters)

Official campaign websites Daniel Ahlers (D) for Senate Mike Rounds (R) for Senate Clayton Walker (I) for Senate