2010Final results
2010 election for U.S. Senate in Colorado
U.S. Senate · Colorado
Michael F. Bennet (D) won with 48.1% of the vote, defeating Ken Buck (R) by 1.6 points.
Michael F. BennetDemocrat · winner
48.1%851,590
Ken BuckRepublican
46.4%822,731
Bob KinseyGreen
2.2%38,768
Maclyn "mac" StringerLibertarian
1.3%22,589
Jason NapolitanoIndependent
1.1%19,415
Charley MillerIndependent
0.6%11,330
J. MoromisatoIndependent
0.3%5,767
1,772,286 votes
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET
The seat over time
D − R margin in this seat's races around 2010
Races before and after
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET
Money in this race
Each line compares the two campaigns on one scale.
Michael F. BennetKen Buck
$13.2M
Raised by the campaign
$5.1M
$13.1M
Spent by the campaign
$4.9M
$155.5K
Cash on hand
$164.9K
Other candidates' campaigns: Jason Napolitano $27.5K · Maclyn "mac" Stringer $1.3K.
Campaign money: FEC, through Dec 31, 2010.
Source: FEC campaign filingsUpdated Dec 31, 2010
The candidates
Michael F. Bennet (D)Ken Buck (R)
Also on the ballot: Bob Kinsey (Green), 2.2%; Maclyn "mac" Stringer (Libertarian), 1.3%; Jason Napolitano (Independent), 1.1%; Charley Miller (Independent), 0.6%; J. Moromisato (Independent), 0.3%