United States Senate elections, 2010
* 2 independents (VT, CT) caucus with the Democrats.
Elections to the United States Senate were held on November 2, 2010, for 37 of the United States Senate's 100 seats. (A special election on January 19, 2010 in Massachusetts was held earlier in the year.) Thirty-four of the elections were for six-year terms to the Senate's "class three", while the other three elections were special elections for shorter terms. Of the 37 elections, 19 featured incumbent Democrats (7 of whom retired or were defeated in the primary) and 18 featured incumbent Republicans (eight of whom retired or were defeated in the primary).
Republicans won four seats held by retiring Democrats and Republicans defeated two incumbent Democrats, for a total gain of six seats. This was the largest number of Republicans gains since the 1994 elections and also the first time since that election that Republicans successfully defended all of their own seats. This was the fourth consecutive election of "class 3" senators where Democrats failed to gain seats and the third consecutive mid-term election held in a president's first term where Republicans picked up seats.
Despite Republican gains, the Democrats retained a majority of the Senate with 51 seats plus 2 independents who caucused with them, compared to a total of 47 Republican-held seats.
- 1 Overview
- 2 Change in composition
- 3 Summary of contests
- 4 Complete list of races
- 4.1 Alabama
- 4.2 Alaska
- 4.3 Arizona
- 4.4 Arkansas
- 4.5 California
- 4.6 Colorado
- 4.7 Connecticut
- 4.8 Delaware
- 4.9 Florida
- 4.10 Georgia
- 4.11 Hawaii
- 4.12 Idaho
- 4.13 Illinois
- 4.14 Indiana
- 4.15 Iowa
- 4.16 Kansas
- 4.17 Kentucky
- 4.18 Louisiana
- 4.19 Maryland
- 4.20 Missouri
- 4.21 Nevada
- 4.22 New Hampshire
- 4.23 New York
- 4.24 New York
- 4.25 North Carolina
- 4.26 North Dakota
- 4.27 Ohio
- 4.28 Oklahoma
- 4.29 Oregon
- 4.30 Pennsylvania
- 4.31 South Carolina
- 4.32 South Dakota
- 4.33 Utah
- 4.34 Vermont
- 4.35 Washington
- 4.36 West Virginia
- 4.37 Wisconsin
- 5 See also
- 6 References
- 7 External links
Twelve incumbents chose not to run for re-election.
|Democrats (6)||Republicans (6)|
Incumbents seeking re-election
Twenty-five incumbents sought re-election.
|Democrats (13)||Republicans (12)|
Shading indicates party with largest share of that line.
|Last election (2008)||57||41||2ID||—||—||—||—||100|
|Before this election||57||41||2ID||—||—||—||—||100|
|Class 1 (2006→2012)||22||9||2ID||—||—||—||—||33|
|Class 2 (2008→2014)||19A||15||—||—||—||—||—||34|
|Class 1 Appointees||2||—||—||—||—||—||—||2|
|Class 2 Appointees||1||—||—||—||—||—||—||1|
|Class 3 Appointees||2||—||—||—||—||—||—||2|
|Held by same party||3||6||—||—||—||—||—||9|
|Replaced by other party||3 Democrats replaced by 3 Republicans||—||—||—||—||—||6|
|Renominated and won re-election||8A||10||—||—||—||—||—||20|
|Renominated but lost re-election||2 Democrats replaced by 2 Republicans||—||—||—||—||—||2|
|Lost renomination but won re-election||—||1||—||—||—||—||—||1|
|Lost renomination but party held||—||1||—||—||—||—||—||1|
|Lost renomination and party lost||1 Democrat replaced by 1 Republican||—||—||—||—||—||1|
|End of this Congress||56||42||2ID||—||—||—||—||100|
A Includes two incumbent appointees who won elections to finish their term or to the next full term.
ID The two Independents joined with the Democrats in their caucus.
Change in composition
Before the elections
After the elections and before the beginning of the 112th Congress
|Note: Four senators were elected in special elections to serve through the end of the 111th Congress. Two of those four simultaneously ran in general elections, held contemporaneously with their special elections, and both won so they therefore began new terms with the new class of senators at the beginning of the 112th Congress.
At the beginning of the 112th Congress
|D39 √||D40 √||D41 √||D42 √||D43 √||D44 √||D45 √||D46 √||D47 √||D48 √|
|R41 O||R42 +||R43 +||R44 +||R45 +||R46 +||R47 +||D51 O||D50 O||D49 O|
|R40 O||R39 O||R38 O||R37 O||R36 O||R35 O||R34 √||R33 √||R32 √||R31 √|
|R21||R22||R23||R24 √||R25 √||R26 √||R27 √||R28 √||R29 √||R30 √|
Summary of contests
Special elections during the preceding Congress
In these special elections, the winner was seated before the next term began on January 3, 2011; ordered by election date.
|Paul Kirk||Democratic||2009 (Appointed)||Incumbent appointee retired.
Winner elected January 19, 2010 to finish term ending January 3, 2013.
|√ Scott Brown (Republican) 51.9%
Martha Coakley (Democratic) 47.1%
Joseph L. Kennedy (Libertarian) 1.0%
|Michael Bennet||Democratic||2009 (Appointed)||Incumbent appointee elected November 2, 2010 to finish term ending January 3, 2011.
Winner also elected to next full term, see below.
|√ Michael Bennet (Democratic) 47.7%
Ken Buck (Republican) 46.8%
Bob Kinsey (Green) 2.2%
Maclyn Stringer (Libertarian) 1.3%
|Ted Kaufman||Democratic||2009 (Appointed)||Incumbent appointee retired.
Winner elected November 2, 2010 to finish term ending January 3, 2015.
|√ Chris Coons (Democratic) 56.6%
Christine O'Donnell (Republican) 40.0%
Glenn Miller (Independent) 2.7%
James Rash (Libertarian) 0.7%
|Roland Burris||Democratic||2009 (Appointed)||Incumbent retired.
Winner elected November 2, 2010 to finish term ending January 3, 2011.
Winner also elected to next term, see below.
|√ Mark Kirk (Republican) 48.2%
Alexi Giannoulias (Democratic) 46.3%
LeAlan Jones (Green) 3.2%
Mike Labino (Libertarian) 2.4%
|Kirsten Gillibrand||Democratic||2009 (Appointed)||Incumbent appointee elected November 2, 2010 to finish term ending January 3, 2013.||√ Kirsten Gillibrand (Democratic) 62.0%
Joseph DioGuardi (Republican) 35.8%
Cecile Lawrence (Green) 0.8
Joseph Huff (Independent) 0.5%
|Carte Goodwin||Democratic||2010 (Appointed)||Incumbent appointee retired.
Winner elected November 2, 2010 to finish term ending January 3, 2013.
|√ Joe Manchin (Democratic) 53.5%
John Raese (Republican) 43.4%
Jesse Johnson (Mountain) 1.9%
Jeff Becker (Constitution) 1.2%
Races leading to the next Congress
(Links to individual elections, below)
(Links to state party articles)
|Incumbent re-elected.||√ Richard Shelby (Republican) 65.3%
William G. Barnes (Democratic) 34.7%
|Alaska||Lisa Murkowski||Republican||2002 (Appointed)
|Incumbent lost renomination,
but re-elected as write-in candidate.
|√ Lisa Murkowski (Republican) (Write-in) 39.5%
Joe Miller (Republican) 35.5%
Scott McAdams (Democratic) 23.5%
|Incumbent re-elected.||√ John McCain (Republican) 59.2%
Rodney Glassman (Democratic) 34.7%
David Nolan (Libertarian) 4.7%
Jerry Joslyn (Green) 1.4%
|Incumbent lost re-election
|√ John Boozman (Republican) 58.0%
Blanche Lincoln (Democratic) 36.9%
Trevor Drown (Independent) 3.3%
John Gray (Green) 1.9%
|Incumbent re-elected.||√ Barbara Boxer (Democratic) 52.1%
Carly Fiorina (Republican) 42.5%
Gail Lightfoot (Libertarian) 1.8%
Marsha Feinland (P&F) 1.3%
Edward Noonan (AIP) 1.3%
Duane Roberts (G) 1.2%
|Colorado||Michael Bennet||Democratic||2009 (Appointed)||Incumbent appointee elected to the next term.
Winner was also elected to finish the term ending January 3, 2011, see above.
|√ Michael Bennet (Democratic) 47.7%
Ken Buck (Republican) 46.8%
Bob Kinsey (Green) 2.2%
Maclyn Stringer (Libertarian) 1.3%
|√ Richard Blumenthal (Democratic) 55.1%
Linda McMahon (Republican) 43.3%
Warren Mosler (Independent) 1.0%
John Mertens (CfL) 0.6%
|Florida||George LeMieux||Republican||2009 (Appointed)||Incumbent retired.
|√ Marco Rubio (Republican) 48.9%
Charlie Crist (Independent) 29.7%
Kendrick Meek (Democratic) 20.1%
Alexander Snitker (Libertarian) 0.5%
|Georgia||Johnny Isakson||Republican||2004||Incumbent re-elected.||√ Johnny Isakson (Republican) 58.1%
Michael Thurmond (Democratic) 39.2%
Chuck Donovan (Libertarian) 2.7%
|Incumbent re-elected.||√ Daniel Inouye (Democratic) 74.8%
Campbell Cavasso (Republican) 21.6%
James Brewer (Green) 2.1%
Jeff Mallan (Libertarian) 0.8%
|Incumbent re-elected.||√ Mike Crapo (Republican) 71.1%
Tom Sullivan (Democratic) 25.0%
Randy Bergquist (Constitution) 3.9%
||Democratic||2009 (Appointed)||Incumbent appointee retired.
Winner also elected to finish term ending January 3, 2011, see above.
|√ Mark Kirk (Republican) 48.2%
Alexi Giannoulias (Democratic) 46.3%
LeAlan Jones (Green) 3.2%
Mike Labino (Libertarian) 2.4%
|√ Dan Coats (Republican) 56.4%
Brad Ellsworth (Democratic) 38.1%
Rebecca Sink-Burris (Libertarian) 5.4%
|Incumbent re-elected.||√ Chuck Grassley (Republican) 64.5%
Roxanne Conlin (Democratic) 33.2%
John Heiderscheit (Libertarian) 2.3%
|Kansas||Sam Brownback||Republican||1996 (Special)
|√ Jerry Moran (Republican) 70.3%
Lisa Johnston (Democratic) 26.2%
Michael Dann (Libertarian) 2.1%
Joe Bellis (Reform) 1.4%
|√ Rand Paul (Republican) 55.8%
Jack Conway (Democratic) 44.2%
|Louisiana||David Vitter||Republican||2004||Incumbent re-elected.||√ David Vitter (Republican) 56.6%
Charles Melancon (Democratic) 37.7%
Randall Hayes (Libertarian) 1.1%
Michael Brown (Independent) 0.8%
|Incumbent re-elected.||√ Barbara Mikulski (Democratic) 61.8%
Eric Wargotz (Republican) 36.3%
Kenniss Henry (Green) 1.1%
Richard Shawver (Constitution) 0.8%
|√ Roy Blunt (Republican) 54.3%
Robin Carnahan (Democratic) 40.6%
Jonathan Dine (Libertarian) 3.0%
Jerry Beck (Constitution) 2.1%
|Incumbent re-elected.||√ Harry Reid (Democratic) 50.2%
Sharron Angle (Republican) 44.6%
None of These Candidates 2.2%
Scott Ashjian (Tea) 0.8%
|New Hampshire||Judd Gregg||Republican||1992
|√ Kelly Ayotte (Republican) 60.2%
Paul Hodes (Democratic) 36.7%
Chris Booth (Independent) 2.0%
Ken Blevens (Libertarian) 1.0%
|New York||Chuck Schumer||Democratic||1998
|Incumbent re-elected.||√ Chuck Schumer (Democratic) 65.4%
Jay Townsend (Republican) 33.0%
Colia Clark (Green) 1.0%
Randy Credico (Libertarian) 0.6%
|North Carolina||Richard Burr||Republican||2004||Incumbent re-elected.||√ Richard Burr (Republican) 55.0%
Elaine Marshall (Democratic) 42.9%
Mike Beitler (Libertarian) 2.1%
|North Dakota||Byron Dorgan||Democratic-NPL||1992
|√ John Hoeven (Republican) 76.2%
Tracy Potter (Democratic) 22.2%
Keith Hanson (Libertarian) 1.6%
|√ Rob Portman (Republican) 57.3%
Lee Fisher (Democratic) 39.0%
Eric Deaton (Constitution) 1.7%
Michael Pryce (Independent) 1.3%
|Oklahoma||Tom Coburn||Republican||2004||Incumbent re-elected.||√ Tom Coburn (Republican) 70.5%
Jim Rogers (Democratic) 26.1%
Stephen Wallace (Independent) 2.5%
Ronald Dwyer (Independent) 0.9%
|Oregon||Ron Wyden||Democratic||1996 (Special)
|Incumbent re-elected.||√ Ron Wyden (Democratic) 57.2%
Jim Huffman (Republican) 39.4%
Bruce Cronk (W.F.) 1.3%
Marc Delphine (Libertarian) 1.1%
Rick Staggenborg (Progressive) 1.0%
|Incumbent lost renomination
|√ Pat Toomey (Republican) 51.01%
Joe Sestak (Democratic) 48.99%
|South Carolina||Jim DeMint||Republican||2004||Incumbent re-elected.||√ Jim DeMint (Republican) 62.4%
Alvin Greene (Democratic) 28.2%
Tom Clements (Green) 9.4%
|South Dakota||John Thune||Republican||2004||Incumbent re-elected.||√ John Thune (Republican) Unopposed|
|Incumbent lost renomination
|√ Mike Lee (Republican) 61.6%
Sam Granato (Democratic) 32.8%
Scott Bradley (Constitution) 5.7%
|Incumbent re-elected.||√ Patrick Leahy (Democratic) 64.4%
Len Britton (Republican) 30.9%
Daniel Freilich (Independent) 1.5%
Cris Ericson (Independent) 1.1%
Stephen Cain (Independent) 1.0%
|Incumbent re-elected.||√ Patty Murray (Democratic) 52.4%
Dino Rossi (Republican) 47.6%
|Incumbent lost re-election
|√ Ron Johnson (Republican) 51.9%
Russ Feingold (Democratic) 47.0%
Rob Taylor (Constitution) 1.1%
Complete list of races
Of the seats with retiring Democrats, three seats were kept by Democrats, and three were won by Republicans.
Of the seats with Democratic incumbents running for re-election, eight Democrats were re-elected, one appointee was elected to finish her term, and one appointee was elected to the next full term. Two lost re-election. One lost renomination and his seat was subsequently won by a Republican.
Of the seats with retiring Republicans, all six were replaced by Republicans.
Of the seats with Republicans incumbents running for re-election, eleven Republicans won re-election. One Republican lost renomination, but the seat was re-elected as a write-in.
Four-term incumbent Republican Richard Shelby, a former Democrat who had switched parties in 1994 when Republicans took control of Congress, was re-elected with 68% of the vote in 2004. The Democratic nominee was William Barnes, a lawyer and Vietnam veteran. Shelby won re-election with 65.2% of the vote.
Incumbent Republican Lisa Murkowski, who was appointed in 2002 by Governor Frank Murkowski (her father), was elected to a full term in 2004 with 48.6% of the vote, sought re-election with fundraising aid from former Governor Sarah Palin. In the 2008 Senate election, Democrat Mark Begich beat incumbent Republican Ted Stevens by a narrow margin, due to an ethics scandal. However, despite earlier fundraising for Murkowski, Palin endorsed and supported Joe Miller instead of Murkowski in the Republican primary. Miller defeated Murkowski in the close primary contest. Sitka Mayor Scott McAdams was the Democratic nominee. Murkowski then ran a write-in campaign against both Miller and McAdams, remaining a Republican, not running as an Independent. Murkowski was re-elected with 39.5% of the votes. These results were contested by Miller; he dropped his suit in December 2010 and Murkowski's victory was certified on December 30, 2010.
2008 Republican presidential nominee and four-term incumbent Republican John McCain had been re-elected with 77% of the vote in 2004. In the Republican primary, McCain defeated two opponents: former U.S. Representative J.D. Hayworth and U.S. Navy veteran and businessman Jim Deakin. Rodney Glassman, former Vice-Mayor of Tucson took the Democratic nomination. John McCain won re-election with 58.7% of the vote.
Two-term incumbent Democrat Blanche Lincoln had been re-elected with 56% in 2004. Lincoln sought re-election and received a tough primary challenge from Lieutenant Governor Bill Halter who raised more than $1 million in his first 48 hours. In the primary, Lincoln finished with less than a majority and faced a runoff with Halter. On June 8, Lincoln won the runoff by a 52% to 48% margin. In the GOP primary, Congressman John Boozman of Arkansas's 3rd congressional district based in northwest Arkansas won a majority to become the Republican nominee. Former Green Beret Trevor Drown, subsequently a member of the Arkansas House of Representatives for Pope and Van Buren counties, ran as a Libertarian, and Mayor John Gray of Greenland ran for the Green Party. John Boozman won the general election with 57.9% of the vote.
Three-term incumbent Democrat Barbara Boxer had been re-elected with 58% in 2004. The last time California elected a Republican to the U.S. Senate was in 1988, when Pete Wilson won a second term. He resigned in 1991 upon being elected governor, and the state has since had both its Senate seats occupied by Democrats. Boxer won the Democratic Senate primary on June 8 with 80% and Boxer faced a tough challenge in the general election from Republican businesswoman Carly Fiorina, a former Hewlett-Packard CEO who defeated State Assemblyman Chuck DeVore, as well as former Congressman Tom Campbell, for the GOP nomination. Donald J. "Don" Grundmann was nominated by the American Independent Party, and Jerry L. Carroll ran as an independent. Barbara Boxer won re-election with 52.2% of the vote to Fiorina's 42.2%.
Following the resignation of one-term U.S. Senator Ken Salazar (D) to become U.S. Secretary of the Interior, Governor Bill Ritter selected Michael Bennet, the former Superintendent of Denver Public Schools, to fill Salazar's seat for the remainder of his term. Both Democrats and Republicans had close fights in their primaries, with Bennet winning the Democratic nomination despite his opponent's receiving prominent support from Bill Clinton. Andrew Romanoff received the endorsement of former President Bill Clinton while Bennet has been endorsed by President Obama. Weld County District Attorney Ken Buck won the GOP nomination over former Lieutenant Governor Jane Norton. Michael Bennet won the general election by a plurality, with 48.1% of the vote.
Five-term incumbent Democrat Christopher Dodd was re-elected with 66% of the vote in 2004. Dodd announced, on January 6, 2010, his intention not to run for re-election. State Attorney General Richard Blumenthal ran as a Democrat, which was expected to improve the Democrats' chances for keeping the seat in the general election, until revelations emerged that he had exaggerated his military record. Former CEO of World Wrestling Entertainment Linda McMahon won the GOP primary. Blumenthal won the general election with 55.1% of the vote.
Ted Kaufman was appointed to continue Joe Biden's term. In 2008, Biden had been simultaneously re-elected and elected Vice President. Biden began his seventh term on January 3, 2009, and he resigned January 15, 2009. Democrat Ted Kaufman, Biden's former chief of staff, was appointed to replace Biden. A special election for the remainder of Biden's term, which expires on January 3, 2015, was held in 2010. Kaufman announced that he would not be a candidate in the special election. The seat will be up for election again in 2014 for a full six-year term. Biden's 2008 opponent, Republican Christine O'Donnell, won an upset primary victory on September 14, 2010 against Representative Mike Castle by 6%. Joe Biden's son, Beau Biden, the incumbent Delaware Attorney General who returned in 2009 from serving in Iraq with the Delaware National Guard, declined to run for the Democratic nomination, New Castle County Executive Chris Coons won the Democratic nomination. Libertarian Jim Rash also ran. The race had been leaning Republican until O'Donnell upset Castle in the Republican primary election. Chris Coons won the special election with 56.6% of the vote.
Republican Senator Mel Martinez resigned from this seat on September 9, 2009. Governor Charlie Crist appointed George LeMieux to finish Martinez's term. LeMieux did not seek election to the full term in 2010. Crist ran against former Speaker of the Florida House of Representatives Marco Rubio for the Republican nomination, but Crist later decided to run as an independent. The initial polls taken after Crist's announcement showed him leading both Rubio and either Democratic candidate. Later polling showed Rubio taking a lead of more than 50%. Rubio beat nine other Republicans for the nomination. Democratic Congressman Kendrick Meek of Florida's 17th congressional district won the Democratic nomination beating several other Democrats including real estate executive Jeff Greene. Marco Rubio won the general election with a 48.9% plurality.
One-term incumbent Republican Johnny Isakson was elected with 58% of the vote in 2004. Isakson won renomination unopposed. Labor Commissioner Mike Thurmond was the Democratic nominee. Isakson won re-election with 58.1% of the vote.
Two-term incumbent Republican Mike Crapo was reelected against only token write-in opposition in 2004. The Democratic nominee in 2010 was Tom Sullivan and the Constitution Party nominee was Randy Lynn Bergquist. Crapo won re-election with 71.1% of the vote.
Roland Burris was appointed to continue Barack Obama's term, and he did not seek re-election in 2010. The election featured both a special election to finish the term ending January 3, 2011, and a general election to begin that day. Candidates included Democratic State Treasurer Alexi Giannoulias, Republican congressman Mark Kirk, Green party journalist LeAlan Jones and Libertarian Michael Labno. Also running as a write-in candidate was Independent Conservative Robert L. "Bob" Zadek. Mark Kirk won the general election with 48.4% of the vote.
Evan Bayh, two-term incumbent Democratic senator and former two-term Governor of Indiana, announced that he wouldn't seek re-election. U.S. Representative Brad Ellsworth of Indiana's 8th congressional district was the Democratic nominee. Lobbyist and former U.S. Senator Dan Coats was the Republican nominee. Running under the Libertarian Party was Rebecca Sink-Burris, a former teacher from Bloomington, Indiana. Two independents attempted to make the ballot for the general election: Don Harris and Timothy Frye. Dan Coats won the general election with 54.6% of the vote.
Five-term incumbent Republican Chuck Grassley was re-elected with 70% in 2004. Grassley ran for re-election and was renominated. Former U.S. Attorney Roxanne Conlin won the Democratic nomination. Grassley won re-election with 64.4% of the vote.
Two-term incumbent Republican Sam Brownback retired and ran for Governor of Kansas. Republican Jerry Moran of Kansas's 1st congressional district narrowly won the GOP primary against Congressman Todd Tiahrt of Kansas's 4th congressional district. Baker University Assistant Dean Lisa Johnston was the Democratic nominee and Joe Bellis ran as the Reform Party candidate. Jerry Moran won the general election with 70.3% of the vote.
Two-term incumbent Republican Jim Bunning had been narrowly re-elected (51-49%) in 2004 against his Democratic opponent, then-State Senator Daniel Mongiardo. Bunning had intended to run for re-election, but state Republican leaders were not supportive. On July 27, 2009, Bunning announced that he would retire. In the primary elections, Republican physician Rand Paul, son of libertarian-leaning U.S. Representative and 2008 Republican presidential candidate Ron Paul (R-Texas), defeated Kentucky Secretary of State Trey Grayson despite Grayson's support by Kentucky's Senior Senator and Senate Minority Leader Mitch McConnell. Democratic Kentucky Attorney General Jack Conway was nominated in his primary over Lieutenant Governor Daniel Mongiardo. Rand Paul won the general election with 55.7% of the vote.
One-term incumbent Republican David Vitter was elected with 51% in 2004, overcoming Louisiana's jungle primary system. Vitter sought re-election in 2010, despite being involved in a prostitution scandal. Congressman Charles Melancon of Louisiana's 3rd congressional district was the Democratic nominee. Vitter won re-election with 56.6% of the vote.
Four-term incumbent Democrat Barbara Mikulski had been re-elected with 65% in 2004. Mikulski faced nominal competition in her primary and was easily renominated. Eleven Republicans dueled for the nomination including Eric Wargotz, president of the Queen Anne's County Commission,. Wargotz won the GOP nomination, joining Richard Shawver (Constitution) and Kenniss Henry (Green). Barbara Mikulski won re-election with 62.2%.
Four-term incumbent Republican Kit Bond was re-elected with 56% in 2004, and this time he did not seek re-election. Congressman Roy Blunt, the former House Majority Whip from Missouri's 7th congressional district, won the Republican nomination beating 10 other Republicans. Democratic Secretary of State Robin Carnahan beat two other candidates for her party's nomination. Midge Potts was the nominee of the Progressive Party of Missouri. The Constitution Party of Missouri had three candidates, and it nominated Jerry Beck. The Libertarian Party had two candidates, and it nominated Jonathan Dine. Glenn Miller sought election as a write-in candidate. Roy Blunt won the general election with 54.3% of the vote.
Four-term incumbent and Senate Majority Leader Harry Reid was re-elected with 61% in 2004. As Reid began his re-election bid, he was considered one of the most vulnerable incumbents in the 2010 election cycle. He faced a tough challenge in the general election from former State Assemblywoman Sharron Angle, who received much support and enthusiasm from the Tea Party and who defeated Nevada Republican Party chairperson Sue Lowden for the GOP nomination. Harry Reid won re-election, 50.3% to Angle's 44.5%.
Three-term incumbent Republican Judd Gregg was re-elected in 2004 with 66%. Gregg did not seek re-election in 2010. The only Democratic candidate was Congressman Paul Hodes of New Hampshire's 2nd congressional district. Republican State Attorney General Kelly Ayotte won the Republican nomination narrowly beating Ovide Lamontagne Self-employed realtor and perennial candidate Kenneth Blevens ran as the Libertarian. Kelly Ayotte won the general election with 60.2% of the vote.
Incumbent Democrat Kirsten Gillibrand had been appointed on January 23, 2009 by the Governor, after then-Senator Hillary Rodham Clinton resigned to become U.S. Secretary of State. The appointment lasted until this special election, the winner of which will serve to the end of the term in January 2013. Gillibrand won the primary against attorney Gail Goode by a margin of three-to-one. In the Republican primary, former Congressman Joe DioGuardi  beat two strong challengers for the GOP nomination. Kirsten Gillibrand won the special election with 62.0%.
One-term incumbent Republican Richard Burr was elected with 52% in 2004. Burr sought re-election and won his party's nomination. Secretary of State Elaine Marshall secured the Democratic nomination. Michael Beitler ran as the Libertarian candidate. Burr won re-election with 54.8% of the vote.
Incumbent Democrat Byron Dorgan announced on January 5, 2010 that he would not seek re-election in 2010. In 2004, he won with 68%. Independent Ralph Nader received 1.32% in North Dakota. State Senator Tracy Potter was the only Democrat to run for the nomination, and he won the Democratic primary election with no competition. Republican former Governor John Hoeven ran and won the Republican nomination at the state primary convention on March 22. Keith Hanson ran as a Libertarian. John Hoeven won the general election with 76.2% of the vote.
Two-term incumbent Republican George Voinovich was re-elected with 64% in 2004. Voinovich did not seek re-election in 2010. Republicans nominated Rob Portman, former Congressman, U.S. Trade Representative, and Office of Management and Budget (OMB) Director and the Democrats nominated Lieutenant Governor Lee Fisher. Eric Deaton, a field service engineer with General Electric, ran as the Constitution Party candidate and Dan La Botz was nominated by the Socialist Party of Ohio, a state-affiliate of the Socialist Party USA. Rob Portman won the general election with 57.3%.
One-term incumbent Republican Tom Coburn was elected with 53% in 2004. Coburn announced that he would be running for a second and final term. Former Republican Party activist Stephen Wallace challenged Coburn as an independent, and the mysterious Jim Rogers won the Democratic nomination without actually campaigning. Coburn won re-election with 70.64%.
Two-term incumbent Democrat Ron Wyden had been re-elected with 64% in 2004. Wyden easily won the Democratic primary nomination, and faced law professor Republican Jim Huffman, in the general election. Ron Wyden won re-election with 57.3% of the vote.
Five-term incumbent Democrat Arlen Specter had been re-elected in 2004 as a Republican by a 53% to 42% margin. On April 28, 2009, Specter announced that he would leave the Republican Party and seek a sixth term in 2010 as a Democrat. Based on polling, the 2004 primary results and a smaller, more conservative Pennsylvania Republican primary electorate, Specter judged that he would lose the Republican primary, and since Pennsylvania law would bar him from running as an independent under such circumstances, he switched parties in 2009 in anticipation of this election. He lost the Democratic primary, however, to retired U.S. Navy Rear Admiral and then-U.S. Representative Joe Sestak of Pennsylvania's 7th congressional district, despite Specter's support from the Democratic establishment. On the Republican side, former U.S. Representative and former President of the Club for Growth Pat Toomey, who came within 1.7% of defeating Specter in the 2004 GOP primary, easily won the GOP nomination. Pat Toomey won the general election with 51.0% of the vote.
Incumbent Republican Jim DeMint was elected with 54% in 2004. DeMint raised $2.2 million for his intended reelection bid. DeMint was easily renominated. He stated in July 2009 that the defeat of health care reform would be Obama's Waterloo. In a surprise, unemployed military veteran Alvin Greene won the Democratic primary. Greene reported no fundraising by mid-October and made few campaign appearances. Tom Clements ran as the candidate of the Green Party. DeMint won re-election with 61.48%.
Three-term incumbent Republican Bob Bennett was re-elected with 69% in 2004. Bennett lost renomination, and the GOP nominated Mike Lee, who faced Utah Alcoholic Beverage Control Commission Chairman, Democrat Sam Granato, in the general election. Lee won the general election with 61.6% of the vote.
Six-term incumbent Democrat Patrick Leahy was re-elected with 71% in 2004. Leahy easily fended off a primary challenge and went on to the general election against Republican Len Britton. Leahy won re-election with 64.4% of the vote.
Three-term incumbent Democrat Patty Murray was re-elected with 55% in 2004. Republican Dino Rossi, who narrowly lost the 2004 and 2008 gubernatorial elections, ran as a Republican. Murray and Rossi advanced to the general election, taking the top two spots in the blanket primary. Patty Murray won re-election with 52.4% of the vote.
Senator Robert Byrd (D) died on June 28, 2010. Democratic Governor Joe Manchin appointed Carte Goodwin to serve until the special election. Goodwin announced that he would not run in the special election. Both parties held their primaries on August 28. Manchin ran against 95-year-old former representative and former Secretary of State Ken Hechler and 2008 Senate candidate Sheirl Fletcher. Manchin won the primary nomination with over 70% of the Democratic vote. 2006 Republican nominee against Robert Byrd, John Raese ran in the GOP primary. State Senator Clark Barnes was another potential candidate. Representative Shelley Moore Capito announced that she would not seek the seat. Raese won the Republican nomination with over 70% of that vote. Jesse Johnson ran as the Mountain Party's nominee. Joe Manchin won the special election with 53.5% of the vote.
Three-term incumbent Democrat Russ Feingold had been re-elected with 55% in 2004. Ron Johnson, a Fox Valley millionaire businessman and political novice, was the Republican nominee. Rob Taylor ran as the Constitution Party nominee. Ron Johnson won the general election with 51.9% of the vote.
- United States House of Representatives elections, 2010
- United States gubernatorial elections, 2010
- United States elections, 2010
- "The Green Papers 2010 U.S. Senate Popular Vote and FEC Total Receipts by Party". Thegreenpapers.com. Retrieved August 20, 2011.
- Member Profile. "Profile for Sen. Richard C. Shelby, Alabama Republican". CQ Politics. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Lisa Murkowski, Alaska Republican". CQ Politics. Retrieved June 13, 2010.
- "Palin to aid Murkowski's 2010 Senate campaign". The Miami Herald. April 8, 2009.[dead link] Cite error: Invalid
<ref>tag; name "murkowski" defined multiple times with different content (see the help page).
- Toeplitz, Shira (August 30, 2010). "Lisa Murkowski concedes defeat to Joe Miller". Politico. Retrieved October 31, 2010.
- Bohrer, Becky (September 18, 2010). "Murkowski mounting write-in bid for Alaska Senate". Associated Press. Retrieved September 18, 2010.
Murkowski faces tough odds with her write-in candidacy. She lost support from the Republican establishment, who backed the Republican nominee, Joe Miller.[dead link]
- "Alaska Senate race could be 'highest stakes spelling bee' in politics". CNN (CNN.com). November 4, 2010. Retrieved November 5, 2010., "'I'm not my party's nominee, but I am a Republican,' [Murkowski] said."
- Member Profile. "Profile for Sen. John McCain, Arizona Republican". CQ Politics. Retrieved June 13, 2010.
- "Arizona - Primary Election Results". Secretary of State. Retrieved August 26, 2010.
- "Arizona US Senatorial Race: Rodney Glassman". Phoenix.org. Retrieved August 26, 2010.
- Member Profile. "Profile for Sen. Blanche Lincoln, Arkansas Democrat". CQ Politics. Retrieved June 13, 2010.
- Kiely, Eugene (March 1, 2010). "Lt. Gov. Halter to challenge Sen. Lincoln in Ark. Democratic primary". USA Today. Retrieved May 27, 2010.
- "Quick Cash for Halter: Liberals Rally to Raise $1 Million - Politics". The Atlantic. March 3, 2010. Retrieved June 13, 2010.
- CNN (June 8, 2010). "Battle lines drawn in Tuesday's primaries". Retrieved June 9, 2010.
- "Source: Boozman to challenge Blanche Lincoln's Arkansas Senate seat". Boston Herald. January 30, 2010. Retrieved February 3, 2010.
- "The Courier, Russellville, Arkansas". Couriernews.com. July 27, 2009. Retrieved June 13, 2010.
- "Arkansas 2009 General Election". Thegreenpapers.com. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Barbara Boxer, California Democrat". CQ Politics. Retrieved June 13, 2010.
- Felde, Kitty (June 3, 2010). "Senator Barbara Boxer could face tough re-election fight". KPCC. Retrieved June 3, 2010.
- "California 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- "Florida 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- "bloomberg.com". bloomberg.com. January 20, 2009. Retrieved June 13, 2010.
- Crummy, Karen (January 2, 2009). "Michael Bennet chosen as next Senator". Denver Post. Retrieved January 2, 2009.
- "Bennet gets big win in Colorado". CNN. August 11, 2010. Retrieved August 11, 2010.
- "Buck announces bid for U.S. Senate seat". Greeleytribune.com. April 28, 2009. Retrieved June 13, 2010.
- Member Profile. "profile". Cqpolitics.com. Retrieved June 13, 2010.
- "Chris Dodd to step aside". The Washington Post. January 4, 2010.
- Connecticut AG Blumenthal to seek Dodd's Senate seat, Reuters (January 6, 2010)
- "Inexperience Wins on Busy Primary Night". CBS News. August 11, 2010. Retrieved November 8, 2010.
- "Kaufman Picked by Governor to Fill Biden Senate Seat (Update3)". Bloomberg.com. November 24, 2008. Retrieved June 13, 2010.
- Brumfield, Susan (November 24, 2008). "Longtime Biden aide picked to fill his Senate seat". Associated Press. Retrieved November 25, 2008.[dead link]
- Yellin, Jessica (September 14, 2010). "Christine O'Donnell wins Delaware GOP Senate primary". CNN. Retrieved September 17, 2010.
- "Beau Biden will not run for father's former Senate seat". The Washington Post. Retrieved May 27, 2010.
- "Delaware 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- "Election 2010: Delaware Senate". Rasmussen Reports. September 16, 2010. Retrieved September 22, 2010.
- Murray, Mark (August 28, 2009). "George LeMieux to replace Mel Martinez". msnbc.com.
- Frolik, Joe (February 20, 2010). "LeMieux not seeking reelection". Cleveland Plain Dealer. Retrieved March 10, 2010.
- "Crist to Run as Independent in FL Sen Race". Liveshots.blogs.foxnews.com. April 28, 2010. Retrieved June 13, 2010.
- "Crist to run for Senate as independent candidate". CNN. April 28, 2010. Retrieved May 27, 2010.
- "Florida 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Johnny Isakson, Georgia Republican". CQ Politics. Retrieved June 13, 2010.
- "7/20/2010 - United States Senator, Isakson". Sos.georgia.gov. Retrieved August 21, 2010.
- To, Contributing; Healy, Patrick; Janofsky, Michael; Luo, Michael; Medina, Jennifer; Pear, Robert; Prez-Pea, Richard; Santora, Marc; Strom, Stephanie; Wakin, Daniel J. (November 4, 2004). "The 2004 Elections: State by State -- West". The New York Times. Retrieved November 6, 2008.
- "Eight-Term Hawaii Sen. Inouye Seeks Re-Election in 2010". Yahoo News. December 11, 2008. Retrieved December 11, 2008.[dead link]
- Member Profile. "Profile for Sen. Michael D. Crapo, Idaho Republican". CQ Politics. Retrieved June 13, 2010.
- "Illinois 2009 General Election". Thegreenpapers.com. Retrieved June 13, 2010.
- "Twitter/Huffington Post Alert". Twitter.com. Retrieved June 13, 2010.
- Bloomberg (February 20, 2010). "Indiana: Congressman Enters Race for Bayh's Senate Seat". The New York Times.
- "Dan Coats Confirms Bid For U.S. Senate". February 10, 2010.
- "Intuit® Small Business | Accounting Software, Pay by Mobile, Free Website Builder". Publicparty.info. Retrieved August 20, 2011.
- "Indiana 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- Tom Beaumont (November 6, 2009). "Conlin to file paperwork next week to seek U.S. Senate seat". Des Moines Register. Retrieved 11-21. Check date values in:
- KCCI. "ELECTION RESULTS: June 8 Primary …view all races - Political News Story - KCCI Des Moines". Retrieved June 9, 2010.
- "Brownback announces Senate retirement". Joplin Globe. December 18, 2008.
- Steve Kraske (November 9, 2008). "Is that the distant sound of primary war drums? Moran, Tiahrt talk U.S. Senate 2010". Kansas City Star. Retrieved November 9, 2008.[dead link]
- Jeffrey Young (January 31, 2009). "Kansan Tiahrt makes Senate bid official". The Hill. Retrieved January 31, 2009.
- "Joe Bellis - 2010 Candidate United States Senate for Kansas". Bellisforsenate.com. Retrieved June 13, 2010.
- "Will Bunning Swing and Miss in 2010?". CQ Politics. April 8, 2009. Retrieved June 13, 2010.
- "Bunning's war cupboard nearly bare". Lexington Herald. January 4, 2009.[dead link]
- Bunning will not seek 3rd term[dead link]
- [dead link]
- "The Scorecard: Elite bashing in Kentucky". Politico.Com. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. David Vitter, Louisiana Republican". CQ Politics. Retrieved June 13, 2010.
- Heather Miller (February 20, 2009). "Vitter discusses economy". The Daily Iberian. Retrieved February 21, 2009.
- The Washington Post, Senator's Number on 'Madam' Phone List, July 10, 2007
- Member Profile. "Profile for Sen. Barbara A. Mikulski, Maryland Democrat". CQ Politics. Retrieved June 13, 2010.
- "WBAL Radio". wbal.com. Retrieved June 13, 2010.
- Raju, Manu (January 8, 2009). "Bond will not seek another term". Politico. Retrieved January 8, 2009.
- "Election News - Progressive Party of Missouri". Progressivepartymo.org. Retrieved June 13, 2010.
- "Elect Jerry Beck". Electbeckussenate.com. March 15, 2010. Retrieved June 13, 2010.[dead link]
- "Jonathan Dine for US Missouri Senator 2010". Votedine.com. Retrieved June 13, 2010.
- "Vote for Glenn Miller". Whty.org. Retrieved June 13, 2010.
- Bresnahan, John (October 25, 2007). "Reid readies for reelection".
- "Profile of Sen. Judd Gregg, New Hampshire Republican". CQ Politics.
- J. Taylor Rushing (April 1, 2009). "Gregg says he definitely won't run again". The Hill.
- "Rep. Hodes will stay in New Hampshire Senate race". The Hill.
- Josh Kraushaar (November 8, 2009). "Lamontagne announces Senate campaign". Politico. Retrieved November 25, 2009.
- "Welcome | Ken Blevens for U.S. Senate 2010". Kblevens.org. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Charles E. Schumer, New York Democrat". CQ Politics. Retrieved June 13, 2010.
- Saltonstall, David (February 1, 2009). "Sen. Chuck Schumer unlikely to see competition in 2010 reelection bid". New York: Nydailynews.com. Retrieved June 13, 2010.
- "N.Y. governor names Clinton successor - CNN.com". CNN. January 23, 2009. Retrieved May 27, 2010.
- [dead link]
- ""Joe DioGuardi, 'American Idol' judge Kara DioGuardi's dad, to run for Kirsten Gillibrand Senate seat", March 12, 2010, New York Daily News". Nydailynews.com. March 12, 2010. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Richard M. Burr, North Carolina Republican". CQ Politics. Retrieved June 13, 2010.
- "Burr wins in N.C.; opponent undetermined". United Press International. May 4, 2010. Retrieved September 19, 2010.
- "Dr. Mike Beitler for U.S. Senate". Beitlerforussenate.org. Retrieved June 13, 2010.
- "North Dakota Sen. Byron Dorgan To Retire". USA Today.[dead link]
- Bjorke, Christopher; Jenny Michael (January 5, 2010). "N.D.'s Sen. Dorgan won't run for re-election in 2010". The Bismarck Tribune. Retrieved January 29, 2010.
- "Inforum|Fargo, Nd". Secure.forumcomm.com. Retrieved August 20, 2011.
- Trygstad, Kyle (January 15, 2010). "Politics Nation - ND Sen Poll: Hoeven Begins Race With Lead". RealClearPolitics. Retrieved June 13, 2010.
- "North Dakota 2010 Midterm Election". Thegreenpapers.com. Retrieved June 13, 2010.
- Plain Dealer file (January 12, 2009). "It's Official Voinovich To Retire". Blog.cleveland.com. Retrieved August 20, 2011.
- "Voinovich to announce retirement". Politico. January 11, 2009.
- "Dan La Botz, Cincinnati School Teacher, Socialist Party Candidate for U.S. Senate". CincinnatiBeacon.com. February 18, 2010. Retrieved May 3, 2010.
- To, Contributing; Healy, Patrick; Janofsky, Michael; Luo, Michael; Medina, Jennifer; Pear, Robert; Prez-Pea, Richard; Santora, Marc; Strom, Stephanie; Wakin, Daniel J. (November 4, 2004). "The 2004 Elections: State by State -- South". The New York Times. Retrieved November 6, 2008.
- "Video: Coburn to seek second term". Tulsa World. June 1, 2009.
- "Oregon 2010 Primary Results: U. S. Senate". The Oregonian. May 18, 2010. Retrieved May 19, 2010.
- Member Profile. "Profile for Sen. Arlen Specter, Pennsylvania Democrat". CQ Politics. Retrieved June 13, 2010.
- "Ben Smith's Blog: Specter switching parties". Politico. Retrieved June 13, 2010.
- MSNBC.com Staff (May 18, 2010). "Sestak beats Specter in Pa. Dem Senate race". MSNBC.
- Member Profile. "Profile for Sen. Jim DeMint, South Carolina Republican". CQ Politics. Retrieved June 13, 2010.
- "DeMint 2010 war chest: $2.2 million".
- To, Contributing; Healy, Patrick; Janofsky, Michael; Luo, Michael; Medina, Jennifer; Pear, Robert; Prez-Pea, Richard; Santora, Marc; Strom, Stephanie; Wakin, Daniel J. (November 4, 2004). "The 2004 Elections: State by State -- Midwest". The New York Times. Retrieved November 6, 2008.
- Member Profile. "Profile for Sen. Robert F. Bennett, Utah Republican". CQ Politics. Retrieved June 13, 2010.
- Weigel, David. "Mike Lee wins in Utah, and so does the tea party", Washington Post, June 23, 2010
- Utah Election Results: Republican for US Senate, Utah Secretary of State, June 22, 2010
- Member Profile. "Profile for Sen. Patrick J. Leahy, Vermont Democrat". CQ Politics. Retrieved June 13, 2010.
- Member Profile. "Profile for Sen. Patty Murray, Washington Democrat". CQ Politics. Retrieved June 13, 2010.
- "W.Va. Gov. Joe Manchin launches Senate campaign; Capito on deck". The Washington Post.
- Rudin, Ken (July 21, 2010). "Capito Won't Run For The Senate In West Virginia, But Hechler, 95, Will". NPR. Retrieved August 21, 2010.
- firstname.lastname@example.org. "Sheirl Fletcher Announces Run for Senate Seat - WOWK-TV". WOWKTV.com. Retrieved August 21, 2010.
- "Raese is in for W.Va. Senate special - Shira Toeplitz". Politico. Retrieved August 21, 2010.
- Member Profile. "Profile for Sen. Russ Feingold, Wisconsin Democrat". CQ Politics. Retrieved June 13, 2010.
- ~ James Madison. "Welcome!". Robtaylorforsenate.com. Retrieved June 13, 2010.
- Party in Power - Shows which party controlled the Senate (as well as the House and Presidency) going back to 1945.
- Senate pickups - Contains a graph of how many Senate seats each party gained during each election from 1946–2008
- Candidates for U.S. Congress at Project Vote Smart
- U.S. Senate from OurCampaigns.com
- Congressional Races in 2010 from Open Secrets (campaign contributions)
- 2010 National Congressional Ballot from Pollster.com
- Senate Race Forecast in 2010 from Pollstered.com
- Election 2010: Senate Elections from Rasmussen Reports
- Florida Senate District 22
- Battle for the Senate from Real Clear Politics
- Senate Races in 2010 from CQ Politics