2016Final results
2016 election for U.S. Senate in South Dakota
U.S. Senate · South Dakota
John Thune (R) won with 71.8% of the vote, defeating Jay Williams (D) by 43.7 points.
John ThuneRepublican · winner
71.8%265,494
Jay WilliamsDemocrat
28.2%104,125
369,619 votes
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 4:52 AM ET
The seat over time
D − R margin in this seat's races around 2016
Races before and after
Source: MIT Election Data and Science LabUpdated Oct 1, 2026, 4:52 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Jay WilliamsJohn Thune
$70.5K
Raised by the campaign
$5.2M
$66.6K
Spent by the campaign
$4.2M
$3.9K
Cash on hand
$10.6M
Campaign money: FEC, through Dec 13, 2016; FEC, through Dec 31, 2016.
Source: FEC campaign filingsUpdated Dec 31, 2016