2016Final results
2016 election for U.S. Senate in Illinois
U.S. Senate · Illinois
Tammy Duckworth (D) won with 54.8% of the vote, defeating Mark Kirk (R) by 15.1 points.
Tammy DuckworthDemocrat · winner
54.8%3,012,940
Mark KirkRepublican
39.7%2,184,692
Kenton McMillenLibertarian
3.2%175,988
Scott SummersGreen
2.1%117,619
5,497,852 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.
Tammy DuckworthMark Kirk
$16.5M
Raised by the campaign
$8.6M
$16.8M
Spent by the campaign
$10.4M
$137.4K
Cash on hand
$220.8K
Campaign money: FEC, through Dec 31, 2016.
Source: FEC campaign filingsUpdated Dec 31, 2016
The candidates
Tammy Duckworth (D)Mark Kirk (R)
Also on the ballot: Kenton McMillen (Libertarian), 3.2%; Scott Summers (Green), 2.1%