2020Final results
2020 election for U.S. Senate in South Dakota
U.S. Senate · South Dakota
Mike Rounds (R) won with 65.7% of the vote, defeating Dan Ahlers (D) by 31.5 points.
Mike RoundsRepublican · winner
65.7%276,232
Dan AhlersDemocrat
34.3%143,987
420,219 votes
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 10:09 AM ET
The seat over time
D − R margin in this seat's races around 2020
Races before and after
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 10:09 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Dan AhlersMike Rounds
$273.8K
Raised by the campaign
$3.7M
$253.1K
Spent by the campaign
$2.5M
$20.7K
Cash on hand
$1.7M
Campaign money: FEC, through Dec 31, 2020.
Source: FEC campaign filingsUpdated Dec 31, 2020