2010 United States Senate election in Colorado

The 2010 United States Senate election in Colorado took place on November 2, 2010, alongside other elections to the United States Senate in other states as well as elections to the United States House of Representatives and various state and local elections. In December 2008, President-elect Barack Obama nominated incumbent U.S. Senator Ken Salazar as Secretary of the Interior. After Salazar resigned from his seat, Democratic governor Bill Ritter appointed Denver Public Schools Superintendent Michael Bennet to fill the seat.

Bennet won a full term, defeating former state House speaker Andrew Romanoff in the Democratic primary, and Republican nominee Ken Buck in the general election. With a margin of 1.7%, this election was the second closest race of the 2010 Senate election cycle after the concurrent one in Illinois.

Nominee

 * Michael Bennet, incumbent U.S. Senator

Eliminated in primary

 * Andrew Romanoff, former speaker of the Colorado House of Representatives

Endorsements

 * Bennet
 * President Barack Obama
 * U.S. Senator Russ Feingold
 * Congresswoman Diana DeGette
 * Congressman Ed Perlmutter
 * Congresswoman Betsy Markey
 * U.S. Senator Mark Udall
 * Congressman Jared Polis
 * Congressman John Salazar
 * Former U.S. Senator Gary Hart
 * Governor Bill Ritter


 * Romanoff
 * Former president Bill Clinton

Results
[[File:CO-Sen 2010 Dem primary.svg|thumb|Results by county: {{legend|#7996e2ff|Bennet}}

{{legend|#7996e2ff|50–60%}}

{{legend|#6674deff|60–70%}}

{{legend|#584cdeff|70–80%}}

{{legend|#1e1dbeff|80–90%}} {{legend|#aade87|Romanoff}}

{{legend|#aade87|50–60%}}]]

Nominee

 * Ken Buck, Weld County District Attorney

Eliminated in primary

 * Jane Norton, former Lieutenant Governor of Colorado

Eliminated in convention

 * Cleve Tidwell, businessman
 * Robert Greenheck
 * Steve Barton

Withdrew

 * Tom Wiens, former state senator

Declined

 * Bob Beauprez, former U.S. Representative for Colorado's 7th congressional district
 * Troy Eid, U.S. Attorney for United States District Court for the District of Colorado
 * Ryan Frazier, Aurora city councilman

Results
[[File:CO-Sen 2010 Rep primary.svg|thumb|Results by county: {{legend|#e27f7f|Buck}}

{{legend|#e27f7f|50–60%}}

{{legend|#d75d5d|60–70%}}

{{legend|#D72F30|70–80%}} {{legend|#ff9955|Norton}}

{{legend|#ff9955|50–60%}}

{{legend|#ff7f2a|60–70%}} Tie

{{legend|#AE8BB1|50%}} ]]

Nominee

 * John Finger

Eliminated in primary

 * Mac Stringer

Major

 * Michael Bennet (D), incumbent U.S. Senator
 * Ken Buck (R), Weld County DA

Minor
Source: Official Candidate List
 * Bob Kinsey (G) (campaign site, archived November 4, 2010, PVS)
 * Charley Miller (I) (campaign site, PVS)
 * J. Moromisato (I) (campaign site, PVS)
 * Jason Napolitano (I) (PVS)
 * Mac Stringer (L) (campaign site, PVS)
 * Bruce E. Lohmiller (G) (Write-in) (Congress.org)
 * Michele M. Newman (I) (Write-in)
 * Robert Rank (R) (Write-in) campaign site,  YouTube campaign video

Campaign
This was one of the most expensive elections in the nation, as more than $30 million was spent by outside organizations. Conservative third party groups hammered Bennet for voting 92% of the time with the Democratic leadership, including voting for healthcare reform and the stimulus package. Liberal third party groups called Buck extremist. Bennet focused on attacking Buck's views on abortion, which he believed should be banned including those of cases of rape and incest. He was also attacked for wanting to eliminate the 17th Amendment and refusing to prosecute an alleged rapist as Weld County district attorney. Planned Parenthood mounted a mail campaign, targeting women voters with the warning that "Colorado women can't trust Ken Buck." Bennet won the women vote by 17 points according to exit polls. After the election, Buck conceded to the Denver Post that the main reason why he lost is because of social issues.

Debates

 * September 12: Sponsored by Club 20 in Grand Junction

Fundraising
These totals reflect the campaign accounts of the candidates themselves, and do not include independent expenditures by other groups.

Counties that flipped from Democratic to Republican

 * Garfield (largest municipality: Glenwood Springs)
 * Bent (Largest city: Las Animas)
 * Mineral (Largest city: Creede)
 * Rio Grande (Largest city: Monte Vista)
 * Archuleta (Largest city: Pagosa Springs)

Counties that flipped from Republican to Democratic

 * Chaffee (largest city: Salida)
 * Ouray (largest city: Ouray)