United States Senate elections, 2012
| Democratic gain Democratic hold
Independent gain Independent hold
Elections to the United States Senate were held on November 6, 2012, with 33 of the 100 seats in the Senate being contested in regular elections whose winners will serve six-year terms beginning January 3, 2013 with the 113th Congress. The Democrats had 21 seats up for election, plus two independents who caucused with the Democrats, while the Republicans had only ten seats up for election. The Democrats gained a net of two seats, leaving them with a total of 53 seats. The Republicans lost a net of two seats, ending with a total of 45 seats. The remaining two senators, both independents, caucused with the Democrats, leaving the majority party with a combined total of 55 seats.
The 2012 presidential election, elections to the House of Representatives, elections for governors in 13 states and territories, and many state and local elections were also held on this date.
This was the third consecutive election of class 1 senators where Democrats gained seats, as well as the third consecutive Senate election held in a presidential election year where the party belonging to the winning presidential candidate gained seats.
- 1 Results summary
- 2 Change in composition
- 3 Complete list of races
- 4 Final predictions before the election
- 5 Complete list of races
- 5.1 Arizona
- 5.2 California
- 5.3 Connecticut
- 5.4 Delaware
- 5.5 Florida
- 5.6 Hawaii
- 5.7 Indiana
- 5.8 Maine
- 5.9 Maryland
- 5.10 Massachusetts
- 5.11 Michigan
- 5.12 Minnesota
- 5.13 Mississippi
- 5.14 Missouri
- 5.15 Montana
- 5.16 Nebraska
- 5.17 Nevada
- 5.18 New Jersey
- 5.19 New Mexico
- 5.20 New York
- 5.21 North Dakota
- 5.22 Ohio
- 5.23 Pennsylvania
- 5.24 Rhode Island
- 5.25 Tennessee
- 5.26 Texas
- 5.27 Utah
- 5.28 Vermont
- 5.29 Virginia
- 5.30 Washington
- 5.31 West Virginia
- 5.32 Wisconsin
- 5.33 Wyoming
- 6 References
- 7 External links
Shading indicates party with largest share of that line.
|Last election (2010)||51||47||2||—||—||—||—||100|
|Before this election||51||47||2||—||—||—||—||100|
|Class 2 (2008→2014)||20||13||—||—||—||—||—||33|
|Class 3 (2010→2016)||10||24||—||—||—||—||—||34|
|Held by same party||5||2||—||—||—||—||—||7|
|Replaced by other party|| 1 Independent replaced by 1 Democrat
1 Republican replaced by 1 Independent
1 Democrat replaced by 1 Republican
|Lost re-election||1 Republican replaced by 1 Democrat||—||—||—||—||—||1|
but held by same party
and party lost
|1 Republican replaced by 1 Democrat||—||—||—||—||—||1|
|End of this Congress||51||47||2||—||—||—||—||100|
Change in composition
Senate composition before the elections
Senate composition as a result of the elections
Complete list of races
Races leading to the next Congress
In these general elections, the winner was seated on January 3, 2013; ordered by state. Percentages may not add to 100% due to rounding & omission of minor candidates.
All of the elections involved the Class 1 seats.
- "U.S. Elections - Detailed Results". The Wall Street Journal. November 25, 2012. Retrieved November 26, 2012.
- "Senate Map - Election 2012". The New York Times. November 25, 2012. Retrieved November 26, 2012.
- "Dave Leip's Atlas of U.S. Presidential Elections".
(linked to summary articles, below)
(Winner in bold)
|√ Jeff Flake (Republican) 49.2%
Richard Carmona (Democratic) 46.1%
Marc Victor (Libertarian) 4.6%
|California||Dianne Feinstein||Democratic||1992 (Special)
|Incumbent re-elected.||√ Dianne Feinstein (Democratic) 62.5%
Elizabeth Emken (Republican) 37.5%
|√ Chris Murphy (Democratic) 54.8% 
Linda McMahon (Republican) 43.1%
Paul Passarelli (Libertarian) 1.7%
|Incumbent re-elected.||√ Tom Carper (Democratic) 66.4%
Kevin Wade (Republican) 29.0% 
Alex Pires (Independent) 3.8%
Andrew Groff (Green) 0.8%
|Incumbent re-elected.||√ Bill Nelson (Democratic) 55.2%
Connie Mack IV(Republican) 42.2% 
Chris Borgia 1.0% (Independent)
Bill Gaylor (Independent) 1.5% 
|Hawaii||Daniel Akaka||Democratic||1990 (Appointed)
|√ Mazie Hirono (Democratic) 62.6%
Linda Lingle (Republican) 37.4%
|Incumbent lost renomination
|√ Joe Donnelly (Democratic) 50.0%
Richard Mourdock (Republican) 44.2%
Andrew Horning (Libertarian) 5.7% 
|√ Angus King (Independent) 52.9%
Charles E. Summers, Jr. (Republican) 30.7%
Cynthia Dill (Democratic) 13.3% 
Danny F. Dalton (Independent) 0.8%
Andrew Ian Dodge (Libertarian) 0.8%
|Maryland||Ben Cardin||Democratic||2006||Incumbent re-elected.||√ Ben Cardin (Democratic) 56.0%
Dan Bongino (Republican) 26.3%
Rob Sobhani (Independent) 16.4% 
Dean Ahmad (Libertarian) 1.2% 
|Massachusetts||Scott Brown||Republican||2010 (Special)||Incumbent lost re-election.
|√ Elizabeth Warren (Democratic) 53.7%
Scott Brown (Republican) 46.3%
|Incumbent re-elected.||√ Debbie Stabenow (Democratic) 58.8%
Pete Hoekstra (Republican) 38.0% 
Scotty Boman (Libertarian) 1.8% 
Harley Mikkelson (Republican) 0.6%
Richard Matkin (Constitution) 0.6%
John Litle (Natural Law) 0.2%
|Minnesota||Amy Klobuchar||Democratic||2006||Incumbent re-elected.||√ Amy Klobuchar (Democratic) 65.2%
Kurt Bills (Republican) 30.6%
Stephen Williams (Independence) 2.6%
Tim Davis 1.1% (Grassroots)
Michael Cavlan 0.5% (Open Progressive)
|Mississippi||Roger Wicker||Republican||2007 (Appointed)
|Incumbent re-elected.||√ Roger Wicker (Republican) 57.2%
Albert N. Gore, Jr. (Democratic) 40.6% 
Thomas Cramer (Constitution Party) 1.2%
Shawn O'Hara (Reform) 1%
|Missouri||Claire McCaskill||Democratic||2006||Incumbent re-elected.||√ Claire McCaskill (Democratic) 54.8%
Todd Akin (Republican) 39.0% 
Jonathan Dine (Libertarian) 6.1%
|Montana||Jon Tester||Democratic||2006||Incumbent re-elected.||√ Jon Tester (Democratic) 48.6%
Denny Rehberg (Republican) 44.9% 
Dan Cox (Libertarian) 6.6%
|√ Deb Fischer (Republican) 57.8% 
Bob Kerrey (Democratic) 42.2% 
|Nevada||Dean Heller||Republican||2011 (Appointed)||Incumbent elected to 1st term after appointment||√ Dean Heller (Republican) 45.9%
Shelley Berkley (Democratic) 44.7%
David Lory VanderBeek (Independent American) 4.9%
None of These Candidates 4.5%
|New Jersey||Bob Menendez||Democratic||2006 (Appointed)
|Incumbent re-elected.||√ Bob Menendez (Democratic) 58.9%
Joe Kyrillos (Republican) 39.4% 
Ken Kaplan (Libertarian) 0.5%
Ken Wolski (Green) 0.5%
Gavin Bard (Independent)
Larry Donahue (Independent)
|New Mexico||Jeff Bingaman||Democratic||1982
|√ Martin Heinrich (Democratic) 51.0% 
Heather Wilson (Republican) 45.3%
Jon Barrie (IAP) 3.6%
Robert L. Anderson (write-in) 0.1%
|New York||Kirsten Gillibrand||Democratic||2009 (Appointed)
|Incumbent re-elected.||√ Kirsten Gillibrand (Democratic) 71.6%
Wendy E. Long (Republican) 27.0% 
Colia Clark (Green) 0.6%
Chris Edes (Libertarian) 0.5%
John Mangelli (Common Sense) 0.34%
|North Dakota||Kent Conrad||Democratic||1986
|√ Heidi Heitkamp (Democratic) 50.24% 
Rick Berg (Republican) 49.32%
Other candidates 0.44%
|Ohio||Sherrod Brown||Democratic||2006||Incumbent re-elected.||√ Sherrod Brown (Democratic) 50.7%
Josh Mandel (Republican) 44.7% 
Scott A. Rupert (Independent) 4.6%
|Pennsylvania||Bob Casey, Jr.||Democratic||2006||Incumbent re-elected.||√ Bob Casey, Jr. (Democratic) 53.7%
Tom Smith (Republican) 44.6% 
Rayburn Douglas Smith (Libertarian) 1.7%
|Rhode Island||Sheldon Whitehouse||Democratic||2006||Incumbent re-elected.||√ Sheldon Whitehouse (Democratic) 64.8%
Barry Hinckley (Republican) 35.0%
|Tennessee||Bob Corker||Republican||2006||Incumbent re-elected.||√ Bob Corker (Republican) 64.9%
Mark Clayton (Democratic) 30.4%
Martin Pleasant (Green) 1.7%
Dr. Shaun Crowell (Libertarian) 0.9%
Kermit Steck (Constitution) 0.8%
|Texas||Kay Bailey Hutchison||Republican||1993 (Special)
|√ Ted Cruz (Republican) 56.5%
Paul Sadler (Democratic) 40.7%
John Jay Myers (Libertarian) 2.1%
David Collins (Green) 0.9%
|Incumbent re-elected.||√ Orrin Hatch (Republican) 65.3%
Scott Howell (Democratic) 30.0%
Shaun Lynn McCausland 3.2%
Daniel Geery (UT Justice) 0.83%
|Vermont||Bernie Sanders||Independent||2006||Incumbent re-elected.||√ Bernie Sanders (Independent) 71%
John MacGovern (Republican) 24.9%
Cris Ericson (Marijuana*) 2%
Pete Diamondstone (Liberty Union) 0.9%
Peter Moss (Peace and Prosperity) 0.8%
Laurel LaFramboise (VoteKISS) 0.3%
|Virginia||Jim Webb||Democratic||2006||Incumbent retired.
|√ Tim Kaine (Democratic) 52.9%
George Allen (Republican) 47.0%
|Incumbent re-elected.||√ Maria Cantwell (Democratic) 60.5%
Michael Baumgartner (Republican) 39.5%
|West Virginia||Joe Manchin||Democratic||2010 (Special)||Incumbent re-elected.||√ Joe Manchin (Democratic) 60.6%
John Raese (Republican) 36.5% 
Bob Henry Baber 3.0% (Mountain)
|√ Tammy Baldwin (Democratic) 51.4%
Tommy Thompson (Republican) 45.9%
Joseph Kexel (Libertarian) 2.1%
Nimrod Y U Allen III (IDEA) 0.6%
|Wyoming||John Barrasso||Republican||2007 (Appointed)
|Incumbent re-elected.||√ John Barrasso (Republican) 75.7%
Tim Chesnut (Democratic) 21.7%
Joel Otto (Country) 2.5%
(linked to summary articles, below)
(Winner in bold)
Special elections during the next Congress
In this special election, the winner was elected in 2013 after January 3; ordered by election date.
|Massachusetts||Mo Cowan||Democratic||2013 (Appointed)||Appointee retired.
Winner elected June 25, 2013.
|√ Ed Markey (Democratic) 54.8%
Gabriel E. Gomez (Republican) 44.8%
|New Jersey||Jeffrey Chiesa||Republican||2013 (Appointed)||Appointee retired.
Winner elected October 16, 2013.
|√ Cory Booker (Democratic) 54.9%
Steve Lonegan (Republican) 44.0%
Final predictions before the election
The table below gives an overview of some final predictions of several well-known institutes and people. What can be seen is that while there were very few mistakes (predictions in the wrong direction; essentially only Montana and North Dakota, by both Sabato's Crystal Ball and FiveThirtyEight), FiveThirtyEight and Princeton Election Consortium had 2-4 races in the Lean categories and no tossups, whereas all other sources had at least eleven races in the middle three categories, and in particular many Tossup races.
* The Democrats include Independent Democrat Joe Lieberman, who ran and won as an independent in 2006 after losing the Connecticut Democratic primary, and Independent Bernie Sanders of Vermont, both of whom caucus with the Democratic Party.
† In Maine, independent Angus King did not declare until after the election which party he would caucus with. Roll Call described the race as Likely Independent. Sabato's Crystal Ball marked it as Leans Independent/Democratic. The Cook Political Report notes King's frontrunner status but without knowing his party, treated the race as a Tossup. RealClearPolitics found that King would be likely to caucus with the Democrats, coloring the map for an independent but putting the race in the Likely Democratic column. FiveThirtyEight stated it was more likely that King caucuses with the Democrats, while officially classifying the race as Likely Independent.
Complete list of races
|This article is part of a series on the|
|United States Senate|
|History of the United States Senate|
|Politics and procedure|
Thirty-three seats were up for election:
- Six Democrats retired.
- Five were replaced by a Democrat.
- One was replaced by a Republican.
- Fifteen Democrats ran for re-election.
- All were re-elected.
- One Independent who caucused with the Democrats retired.
- He was replaced by a Democrat.
- One Independent who caucused with the Democrats ran for re-election.
- He was re-elected.
- Three incumbent Republicans retired.
- Two were replaced by Republicans.
- One was replaced by an Independent who caucuses with the Democrats.
- Seven Republicans ran for re-election
- Five were re-elected.
- One lost to a Democrat.
- One lost renomination and was replaced by a Democrat.
Three-term incumbent and Senate Minority Whip Republican Jon Kyl, who was re-elected in 2006 with 53% of the vote, announced he would not seek a fourth term in 2012. Republican Representative Jeff Flake won the August 28 primary with 69.1% of the vote, against three contenders, including real estate investor Wil Cardon  who polled 21.2%. On the Democratic side, former U.S. Surgeon General Richard Carmona won the primary election, which was held August 28, 2012. The candidates faced Libertarian Marc Victor and independents Ian Gilyeat and Michael F. Meyer on Nov. 6.
Flake won the election with 49.7% of the vote against Carmona's 46.2% and Victor's 4.6%.
Three and one-third term incumbent Democrat Dianne Feinstein was re-elected in 2006 with 59% of the vote, and was re-elected. Feinstein finished first in the state's new blanket primary, in which the top two candidates advance to the general election regardless of party.
Feinstein won with 61.6% of the vote.
Four term incumbent Joe Lieberman, an independent who caucused with the Democratic Party, decided not to seek re-election in 2012. Lieberman sat as a Democrat until 2006, when he was defeated by Ned Lamont in the Democratic primary; he then ran as an independent in the general election and he won. He then caucused with the Democrats as an "Independent Democrat."
Former Connecticut Secretary of the State Susan Bysiewicz and Congressman Chris Murphy competed for the Democratic nomination. Linda McMahon, the 2010 Republican Senate nominee, and former Congressmen Chris Shays competed for the GOP nomination. Murphy and McMahon won their respective primaries on August 14. They faced Libertarian Paul Passarelli in the general election.
Murphy won with 55.1% of the vote against McMahon's 43.3% and Passarelli's 1.7%.
Carper won with 66.4% of the vote.
Two-term incumbent Democrat Bill Nelson was reelected with 60% of the vote in 2006 against controversial former Secretary of State of Florida Katherine Harris. Connie Mack IV, Representative from Florida's 14th congressional district, was the Republican nominee, having won the primary with 58.7% of the vote. The two Independents also seeking election in this race were Chris Borgia and Bill Gaylor.
Nelson won with 55.2% of the vote.
Former Governor Linda Lingle won the Republican nomination. In the Democratic primary, Congresswoman Mazie Hirono defeated former Congressman Ed Case, who challenged Akaka for the Democratic nomination in 2006. Lingle and Hirono previously faced each other in Hawaii's 2002 gubernatorial election, with Lingle winning with 52% of the vote.
Hirono was elected with 62.6% of the vote.
Republican Richard Lugar, who in 2006 won his sixth term without a Democratic opponent, was defeated in the 2012 primary election by Richard Mourdock, who criticized Lugar for his willingness to vote with Democrats on key issues. According to Indiana law, Lugar could not be a candidate in the election (R) (e.g. under a third party or as independent) after losing the primary. Mourdock won the primary 61% to 39%. Congressman Joe Donnelly, the Democratic nominee, won the election against him with 50% of the vote, leaving Mourdock with 44.3% and Libertarian Andrew Horning with 5.7%.
On February 28, 2012, Snowe suddenly announced her retirement, saying she did not want to spend another six years in the Senate's hyper-partisan environment. Popular former Governor Angus King, an independent, announced his candidacy and was considered the front-runner for the general election. King did not reveal which, if any, party he would caucus with. Scott D'Amboise, considered a conservative, announced in February 2010 that he would run against Snowe in the Republican primary. Libertarian candidate Andrew Ian Dodge also announced a challenge to Snowe. After Snowe's announcement, other Republicans got into the race, including Secretary of State Charles Summers, state Treasurer Bruce Poliquin, and former state Senator Richard A. Bennett.
Former Maine Secretary of State Matthew Dunlap, a Democrat, announced in early November 2011 that he was running in the Democratic primary. Also in November, State Representative Jon Hinck announced he would run in the Democratic primary. Democratic State Senator Cynthia Dill announced her candidacy in January.
The primary election was held on June 12. Cynthia Dill won the Democratic nomination with 44% of the vote and Charlie Summers took the Republican nomination with 32% of the vote. The two faced Independent former governor Angus King, Andrew Ian Dodge on the Libertarian line, and two other independents: Ex-DEA Agent & USAF Veteran, Danny Dalton and Yarmouth Town Council Chair, Steve Woods.
After winning the general election, King stated he would caucus with the Democrats.
First-term incumbent Democrat Ben Cardin was elected in 2006 with 54% of the vote against former Maryland Lt. Gov. Michael S. Steele. Cardin ran against Independent candidate S. Rob Sobhani, Republican former U.S. Secret Service agent Daniel Bongino, and Libertarian Dr. Dean Ahmad, a Palestinian refugee. Eric Wargotz, the Republican nominee in 2010 had considered entering the race but ultimately decided against it.
Cardin won re-election with 56% of the vote, with 26% for Bongino, 16% for Sobhani, and 1% for Ahmad.
Eight-term Democrat Ted Kennedy was re-elected in 2006, but died in August 2009. Paul G. Kirk was appointed as the interim senator by Governor Deval Patrick, and served until Republican state legislator Scott Brown was elected in a January 2010 special election. He was the first Republican senator to be elected in Massachusetts since 1972. Brown ran for election to a full term. Harvard Law School professor Elizabeth Warren, the Democratic nominee, won the seat with 53.8% of the vote.
Two-term incumbent Democrat Debbie Stabenow was re-elected in 2006 with 57% of the vote to 41% for Oakland County Sheriff and former State Senate Majority Leader Michael Bouchard after narrowly defeating Republican incumbent Spencer Abraham in 2000.
One-term incumbent Democrat Amy Klobuchar was elected in 2006 with 58% of the vote. Senator Klobuchar's approval ratings, last reported at 59%, have steadily risen since her election in November 2006. Her quick response to the I-35 bridge collapse in her home city of Minneapolis and her travels around the state solidified her popularity with the citizens of Minnesota.
Senator Klobuchar won re-election with 65.2% of the vote to Bills' 30.5%.
One-term incumbent Republican Roger Wicker was appointed after former Senate Majority Leader Trent Lott announced on November 26, 2007 that he was going to resign by the end of 2007. Wicker defeated former Governor Ronnie Musgrove in the 2008 special election.
On March 13, Wicker won the primary election with 89% of the vote, and faced Albert N. Gore Jr. of Starkville, who won the Democratic primary with 57% of the vote, as well as Libertarian candidate Dr. Shaun Crowell, Constitution Party candidate Thomas Cramer, and Reform Party candidate Shawn O'Hara.
In the November election, Wicker won re-election with 57% of the vote, with Democrat Albert Gore (no relation to former U.S. Vice President Al Gore) winning 41% of the vote and 2% of the vote going to the minor party candidates.
Democrat Claire McCaskill was elected in 2006 with 49.6% of the vote, defeating then-incumbent Jim Talent. McCaskill was re-elected with no prominent Democrat challenging her. The primary election was held August 14.
Representative Todd Akin won the Republican nomination. Libertarian nominee Jonathan Dine also contested the election.
Republican primary contenders included Congressman Todd Akin, former state Treasurer Sarah Steelman, and businessman John Brunner. Jim Talent declined to run again, and attorney Ed Martin and former Missouri GOP Chair Ann Wagner were instead eyeing Missouri's 2nd Congressional District.
McCaskill won re-election with 55% of the vote to Akin's 39% and Dine's 6%.
One-term incumbent Democrat Jon Tester was elected in 2006 by a 49.2% to 48.3% margin, narrowly defeating incumbent Conrad Burns. Tester sought re-election, facing Republican Congressman Denny Rehberg and Libertarian Dan Cox.
Tester won with 48.6% of the vote against Rehberg's 44.6% and Cox's 6.6%.
Two-term incumbent and former Governor Democrat Ben Nelson did not seek re-election in 2012. Former Governor of Nebraska Bob Kerrey, who held the Senate seat from 1989 to 2001, won the Democratic nomination.
Republican John Ensign won his second term in the Senate in 2006 with 55% of the vote, defeating Democrat Jack Carter. In 2009, Ensign admitted to an affair with a campaign staffer. He initially announced that he was running for re-election, but in March 2011 announced that he would resign effective May 2011, and would not seek reelection. Governor Brian Sandoval appointed Republican Congressman Dean Heller to succeed him.
One-term incumbent Democrat Bob Menendez became the first Hispanic Senator to represent New Jersey in January 2006 when Former Senator Jon Corzine appointed him to the office after having resigned to become Governor, following his election to said office in November 2005. Menendez comfortably defeated Republican state Senator Tom Kean, Jr., son of popular former Governor and 9/11 Commission Chairman Tom Kean and was elected to a full term in November 2006.
The Republican Party nominee was state Senator Joseph M. Kyrillos of Monmouth County. Independent candidates include small business owner David Dranikoff, whose platform focuses mainly on the national debt and financial reform, alternative journalist Gavin Bard, a labor activist and anarcho-syndicalist who declared he will run as an independent based on major campaign tenets of opposing any regulation placed on the internet, abolishing CEOs, and convincing Sega to make the final game in the Shenmue series, as well as Daryl Mikell Brooks, and Gwen Diakos. Rounding out the busy ballot were Libertarian Kenneth R. Kaplan, Socialist Greg Pason, Ken Wolski of the Green Party.
Five-term incumbent Democrat Jeff Bingaman was re-elected in 2006 with 70.6% of the vote. Bingaman decided to retire. Republicans running included businessman former U.S. Representative Heather Wilson, and businessman Greg Sowards. Wilson won the Republican primary with 70% of the vote. The Independent American Party nominated Jon Barrie to run for the seat.
The primaries were held on June 5.
Heinrich won the open seat in the November election with 51.0% of the vote to Wilson's 45.3%.
Two-term Democrat Hillary Rodham Clinton was re-elected in 2006 with 67% of the vote. After narrowly losing the 2008 Democratic Presidential nomination to Barack Obama, she resigned on January 21, 2009 when the Senate confirmed her as Secretary of State. On January 23, Governor David Paterson appointed Congresswoman Kirsten Gillibrand to the seat. Gillibrand won a special election in 2010 with 61.2% of the vote, and was re-elected. Conservative attorney Wendy E. Long prevailed by a sizeable margin in the Republican primary. Long was also designated as the nominee for the Conservative Party of New York State, and appeared on its ballot line as well as the Republican Party line in the general election. Dr. Scott Noren of Ithaca NY ran as an Independent/Unaffiliated candidate against Senator Gillibrand and has a major student loan reform and anti-fracking platform, but didn't make the ballot. John Mangelli, a first time runner for office ran as an independent candidate under the common sense party made the ballot. Chris Edes was the Libertarian Party candidate running on the issues of fiscal solvency, civil liberties and constitutional government. In 2012, Gillibrand won another term, with 72% of the vote.
Four-term incumbent Democrat Kent Conrad was re-elected in 2006 with 69% of the vote. Conrad decided to not run for re-election in 2012. U.S. Representative Rick Berg announced his candidacy as a Republican. State Public Service Commissioner Brian Kalk initially announced his candidacy as well, but since dropped it to run for the at large congressional seat held by Berg. On November 8, 2011, former state Attorney General Heidi Heitkamp announced that she would be running for the Democratic nomination. On Election Day, Heitkamp defeated Berg in an upset win of a margin of approximately 50.5% to 49.5%. This was the closest senate race of 2012. Heitkamp won by a razor thin margin of about 3000 votes.
One-term incumbent Democrat Sherrod Brown was elected in 2006 with 56% of the vote, defeating then-incumbent Mike DeWine, whose popularity suffered due to scandals involving former Republican Governor Bob Taft and ex-Congressman Bob Ney. Brown was challenged by Ohio State Treasurer Josh Mandel in the general election, Brown was re-elected with 50.3 percent of the vote to Mandels 45.1%.
Brown won re-election, 50.7%-44.7% 
One-term incumbent Democrat Bob Casey, Jr., the son of popular former Governor Bob Casey, was elected in 2006 with 58.7% of the vote, defeating then-incumbent Rick Santorum. He was the first Democrat elected to a full term in the U.S. Senate from Pennsylvania since 1962. Casey will seek re-election. He will face Republican candidate, Tom Smith, a businessman and former town supervisor, and Libertarian candidate, Rayburn Douglas Smith. Casey won re-election with 53.5% of the vote to Tom Smith's 44.8% and Rayburn Smith's 1.7%.
Businessman Barry Hinckley announced that he would run against Whitehouse in the general election. Whitehouse defeated Hinckley and won re election to a second term with 65.0% of the vote to Hinckleys 35.0%.
One-term incumbent Republican Bob Corker was elected in 2006 with 50.7% of the vote. He narrowly defeated then-Congressman Harold Ford, Jr.. Corker set up "the Bob Corker for Senate 2012 committee" on November 8, 2006, or one day after winning a six-year term. In November 2011, country music singer Hank Williams, Jr. expressed an interest in challenging Corker for the GOP nomination, but did not enter the primary. The primary election was held August 2, with Corker receiving 85% over four opponents (Zach Poskevich, Fred Anderson, Mark Twain Clemens, and Brenda Lenard).
Corker's opponents were Mark E. Clayton, who won 30% in a seven-way Democratic primary, Libertarian candidate, Dr. Shaun Crowell, Kermit Steck (Constitution Party), Martin Pleasant (Green Party), and independents David Gatchell, James Higdon, Michael Joseph Long, Troy Stephen Scoggin, and Jacob Maurer.
Corker was re elected to a second term with 64.9% of the vote to his opponents 30.4%.
Three-term incumbent Republican Kay Bailey Hutchison was re-elected in 2006 with 62% of the vote despite a poor overall climate for Republicans, who lost control of both chambers of Congress that year. She announced in 2007 that she would not seek re-election, and she ran unsuccessfully for the Republican nomination for Texas Governor in 2009. For the Republicans, former Texas Solicitor General Ted Cruz won in a runoff election against Texas Lt. Governor David Dewhurst 57% to 43%.. Former SMU Mustangs running back and ESPN analyst Craig James, and former Dallas mayor Tom Leppert were also candidates. In the May 29 primary, Dewhurst won 45% to Cruz's 34%.
Cruz won the 2012 Republican nomination for the United States Senate seat being vacated by Kay Bailey Hutchison. He defeated Lieutenant Governor David Dewhurst in the Republican primary runoff, 57-43 percent, on July 31, 2012.
Dallas businessman John Jay Myers won the Libertarian primary with 78.9% of the vote, to become that party's candidate for Senate.
David Collins ran as the Green Party Candidate
Ted Cruz won the general election with 56.6% of the vote to Sadlers' 40.5% and Myers' 2.1%.
Six-term incumbent and former Senate Judiciary Committee Chairman Republican Orrin Hatch was re-elected in 2006 with 62% of the vote. He ran for re-election. Though Hatch remains popular with Utahns in general, he was viewed by many in the Utah Republican Party as too moderate, and many names were floated as potential challengers. The name most frequently mentioned was that of conservative Congressman Jason Chaffetz, who had criticized Hatch, but Chaffetz announced on August 22, 2011, that he would not run against Hatch. Also frequently mentioned was state Senator Dan Liljenquist. At the Utah Republican Party Caucus held on March 15, 2012, it was determined that state Senator Liljenquist would challenge US Senator Hatch in the June 26, primary. Hatch won the primary election with 66% of the vote.
Among Democrats, Scott Howell, former state Senator and 2000 US Senate nominee, defeated Pete Ashdown, CEO of XMission and 2006 nominee for U.S. Senate, in the Utah Democratic Party caucus to secure the nomination to challenge the Utah Republican Party nominee for the US Senate seat currently held by US Senator Orrin Hatch.
Hatch defeated Howell on Election Day November 6, 2012 taking 65.2% of the vote to Howells 30.2%
One-term incumbent Bernie Sanders is an independent Senator (and self-described democratic socialist) who caucuses with the Democrats and won election with 65.4% of the vote in 2006 after Jim Jeffords, also an independent, retired.
Sanders won re election to a second full term with 71.0% of the vote to MacGoverns 24.9%.
One-term incumbent Democrat Jim Webb was elected in 2006 by a margin of 0.6%, narrowly defeating then-incumbent George Allen in the biggest upset of the 2006 elections. Announcing that he did not want to spend his life in politics, Webb said he will not run for re-election. On the Democratic Side, former Governor of Virginia and DNC chairman Tim Kaine was unopposed for the nomination.
The Republican Party of Virginia decided that its nominee would be determined through a primary, as opposed to a state convention which had been used in more recent years. On January 24, 2011, George Allen announced that he would seek the Republican nomination. Jamie Radtke, head of the Virginia Tea Party Patriots, filed papers to run for the Republican nomination. Also considering a run for the Republican nomination were state Del. Robert G. Marshall (R-Manassas) and Corey Stewart, the chairman of the Prince William County Board of Supervisors. Marshall ran for the U.S. Senate in 2008, narrowly losing the Republican nomination at the state convention to former Governor Jim Gilmore by only 69 votes.
Kaine won the race to Succeed Jim Webb in the November 6, 2012 general election, capturing 53.0% of the vote to Allen's 47.0%. Kaine will take office when Webbs current term expires on January 3, 2013.
Two-term incumbent Democrat Maria Cantwell was re-elected in 2006 with 57% of the vote over Republican businessman Mike McGavick. In her 2012 reelection, she will be challenged by Republican state Senator Michael Baumgartner, a former U.S. State Department employee who represents a legislative district in the eastern part of the state.
Cantwell won re-election 60.5%-39.5% 
Democratic Senator Robert Byrd, the longest serving U.S. Senator in history, was re-elected to his ninth term in 2006 but died in office on June 28, 2010. In the November 2010 special election to fill this seat, Democratic Governor Joe Manchin was elected, with 53.5% of the vote. Senator Manchin defeated Sheirl Fletcher in the May 15 Democratic primary election,  to run for a full term.
Bob Henry Baber was the candidate of the "The Mountain Party", the West Virginia affiliate of the Green Party.
Four-term incumbent Democrat Herb Kohl, owner of the NBA's Milwaukee Bucks and member of the founding family of the Kohl's department store chain, announced he would not seek reelection in 2012. He was reelected in 2006 with 67% of the vote.
U.S. Representative Tammy Baldwin announced her intention to run for the seat on September 6. Other potential candidates for the Democrats include former Dane County Executive Kathleen Falk, and Madison biotechnology executive Kevin Conroy. Both candidates declined to run and Baldwin became the only Democratic nominee.
On the Republican side, Business Manager Eric Hovde Former Congressman Mark Neumann, Speaker of the Wisconsin State Assembly Jeff Fitzgerald, and former Governor and former Secretary of Health and Human Services, Tommy Thompson confirmed their candidacies for the seat. The primary was held August 14. Thompson won the Republican nomination with 34% of the vote. Hovde came in second with 31%. Baldwin was unopposed in the Democratic primary and won.
The Libertarian candidate was Joseph Kexel, an IT consultant in Kenosha.
Nimrod Allen III, a former United States Marine, ran as an independent. Baldwin defeated Thompson and Kexel on election night with 51.4%, with the latter candidates getting 45.9% and 2.1%, respectively.
One-term incumbent Republican Dr. John Barrasso was appointed to the Senate in 2007 after the death of Republican Craig L. Thomas and won a special election in 2008 to complete Thomas's term. He defated Democrat Tim Chesnut, a member of the Albany County Board of Commissioners and rancher Joel Otto who ran on the "Wyoming Country" line.
- "FEDERAL ELECTIONS 2012 Election Results for the U.S. President, the U.S. Senate and the U.S. House of Representatives" (PDF). July 2013. Retrieved August 16, 2013.
- Jonathan Weisman (November 6, 2012). "Democrats Keep Control of the Senate". The New York Times.
- Naftali Bendavid (November 6, 2012). "Democrats Retain Control of U.S. Senate". The Wall Street Journal.
- Catanese, David (February 10, 2011). "Kyl to retire, won't seek another term – David Catanese". Politico.Com. Retrieved February 14, 2011.
- Tang, Layla (February 14, 2011) "U.S. Rep. Flake announces Senate bid", KGUN9-TV. Retrieved February 14, 2011.
- Abby Livingston,Richard Carmona Announces Arizona Senate Bid, Roll Call, November 10, 2011
- "Marc Victor for US Senate, Libertarian". Retrieved December 28, 2012.
- "Republican Elizabeth Emken to run against Sen. Dianne Feinstein". The Sacramento Bee. November 28, 2011. Retrieved November 28, 2011.
- "Lieberman Announces He Will Retire in 2012". Fox News. January 19, 2011. Retrieved February 14, 2011.
- Catanese, David (January 18, 2011). "Connecticut's Bysiewicz to announce for Senate – David Catanese". Politico.Com. Retrieved February 14, 2011.
- Jon Terbush (September 20, 2011). "Former Wrestling CEO Linda McMahon Launches Second Senate Bid". Businessinsider.com. Retrieved January 20, 2012.
- "Passarelli for Senate 2012". Passarelli4senate.com. Retrieved June 27, 2011.
- "Kevin L. Wade for Senate 2012". wadeforussenate.com. May 28, 2011. Retrieved May 28, 2012.
- Businessman Alex Pires to run for U.S. Senate (wgmd.com)
- Catanese, David (October 26, 2011). "Connie Mack to enter Fla. Senate race – David Catanese". Politico.Com. Retrieved January 20, 2012.
- Iraq vet Chris Borgia announces US Senate run (Orlando Sentinel)
- qualifies for U.S. Senate Run
- Gaylor biography
- Mascaro, Lisa (March 3, 2011). "Democrat Daniel Akaka of Hawaii to retire from U.S. Senate". Los Angeles Times. Retrieved December 29, 2011.
- Coyne, Tom (August 11, 2010). "Lugar expects to seek 7th Senate term in 2012". Chicago Tribune.
- Horning to run for U.S. Senate
- "Larry J. Sabato's Crystal Ball " Senate". Centerforpolitics.org. January 6, 2011. Retrieved February 14, 2011.
- "Dill sticks in Senate race". The Forecaster (The Forecaster). March 7, 2012. Retrieved March 12, 2012.
- "Angus King steps into Maine Senate race". CNN. March 6, 2012. Retrieved March 6, 2012.
- "Ex-Secret Service agent Daniel Bongino jumps into Maryland Senate race against Cardin – Political Hotsheet". CBS News. Retrieved June 27, 2011.[dead link]
- "Rob Sobhani Independent 2012".
- "Libertarian Party Candidates-2012".
- "Todd Akin Announces Missouri Senate Bid : Roll Call Politics". Rollcall.com. Retrieved June 27, 2011.
- Catanese, David (February 5, 2011). "Rehberg announces: 'It's for the majority' – David Catanese". Politico.Com. Retrieved February 14, 2011.
- "Ben Nelson retiring from Senate". Politico. December 27, 2011.
- Blake, Aaron; Cillizza, Chris (February 27, 2012). "Bob Kerrey changes his mind, will run for Senate, source says". The Washington Post. Retrieved February 27, 2012.
- ""In a choice between experience and honesty, give us honesty every time. Donahue strikes us as honest and has the most well thought-out ideas." "...he has sound ideas and could hit the ground running in Washington, if elected." * – Home". Donahueforcongress.com. October 24, 2010. Retrieved June 27, 2011.
- "Democratic Sen. Bingaman to Retire, Sources Say". Fox News. February 18, 2011. Retrieved February 18, 2011.
- "Rep. Heinrich running for Senate". UPI.com. April 2, 2011. Retrieved April 2, 2011.
- "Conrad Will Not Run for Re-Election". Politicalwire.com. January 18, 2011. Retrieved February 14, 2011.
- Shira Toeplitz. "Heitkamp Makes N.D. Senate Bid Official : Roll Call Politics". Rollcall.com. Retrieved November 8, 2011.
- Tom Shevlin (March 22, 2011). "Newporter Hinckley to Challenge Newporter Whitehouse for Senate Seat". Newport Now.com. Retrieved June 27, 2011.
- Catanese, David (January 13, 2011). "KBH won't run for reelection – David Catanese". Politico.Com. Retrieved February 14, 2011.
- Scharrer, Gary (December 19, 2011). "Former rep files for Senate, filling Dem void left by Sanchez". Houston Chronicle. Retrieved December 20, 2011.
- "2012 VOTE CRIS ERICSON – UNITED STATES MARIJUANA PARTY". Crisericson.com. Retrieved June 27, 2011.
- Smith, Ben (February 9, 2011). "Webb won't seek reelection – Ben Smith". Politico.Com. Retrieved February 14, 2011.
- "George Allen to announce Senate bid Monday – David Catanese". Politico.Com. Retrieved February 14, 2011.
- Kindy, Kimberly (May 13, 2011). "Wisconsin Senator Herb Kohl retires". The Washington Post.
- "Kyl Stays Tight-Lipped on Political Future". Roll Call. Retrieved February 14, 2011.
- "Arizona Congressman Announces U.S. Senate Bid". Fox News. Retrieved February 14, 2011.
- McCarty, Alicia (November 8, 2011). 2, 2011/2012-elections-preview-west/51128694/1 "A look ahead to the key races in the West in 2012" Check
|url=scheme (help). USA Today. Retrieved December 27, 2011.
- "Emken Receives GOP Endorsement for US Senate".
- "Lieberman won't run again | News from southeastern Connecticut". The Day. Retrieved February 14, 2011.
- Vigdor, Neil (February 18, 2011). "McMahon 'leaning' toward 2012 Senate run". Greenwich Time. Archived from the original on July 11, 2011. Retrieved February 19, 2011.
- Neil Vigdor; Ken Dixon (August 15, 2012). "McMahon, Murphy coast to Senate primary wins". StamfordAdvocate.com. Retrieved September 1, 2012.
- Catanese, David (November 18, 2010). "Tom Carper to Harry Reid: Pick 2 chairmen". Politico.
- "Daniel Akaka Retiring"
- "Former Hawaii Gov. Linda Lingle wins GOP nomination in Hawaii for US Senate". Fox News. August 12, 2012.
- "Most Popular E-mail Newsletter". USA Today. May 8, 2012.
- Peleo-Lazar, Christopher (March 10, 2011). "Could Lugar Run As An Independent?". National Journal.
- "Maine senator will not seek re-election". CNN. February 28, 2012.
- Thistle, Scott (May 26, 2012). "King could be effective in the Senate without a caucus, former independent senator says". Bangor Daily News.
- "Republican Scott D'Amboise to Challenge Snowe in 2012". As Maine Goes. February 8, 2010. Retrieved February 14, 2011.
- "Tea partier Andrew Ian Dodge launches campaign against Snowe". Washington Post. February 11, 2011. Retrieved March 9, 2011.
- "Another newcomer enters U.S. Senate race against incumbent Senator Ben Cardin".
- Fritze, John (April 3, 2012). "Ben Cardin wins Senate primary". The Baltimore Sun. Retrieved April 3, 2012.
- "Ex-agent Bongino wins Republican Senate primary; will face Sen. Benjamin Cardin in November". April 4, 2012. Retrieved April 4, 2012.[dead link]
- Shane D'Aprile (December 21, 2010). "GOP senators up in 2012 face primary threats because of START support". The Hill.
- Rizzuto, Robert (June 2, 2012). "Elizabeth Warren lands party endorsement with record 95 percent support at Massachusetts Democratic Convention". The Republican. Retrieved June 2, 2012.
- "Massachusetts". The New York Times.
- "SurveyUSA News Poll #15225". Surveyusa.com. Retrieved May 13, 2011.
- "Trent Lott announces his resignation - Politics". MSNBC. November 26, 2007. Retrieved June 29, 2010.
- "Senate Race 2012". pressreleases.kcstar.com. November 23, 2010. Retrieved December 1, 2010.
- "GOP Rep. Todd Akin to run for Senate in Missouri". USA Today. May 17, 2011. Retrieved May 20, 2011.
- "Sarah Steelman for U.S. Senate 2012". sarahsteelman.com. November 29, 2010. Retrieved December 1, 2010.
- Lieb, David A. "St. Louis businessman might challenge McCaskill in Senate race". Columbia Missourian. Retrieved May 13, 2011.
- Lambrecht, Bill (January 27, 2011). "Talent says no to Missouri Senate bid". St. Louis Post-Dispatch. Retrieved January 27, 2011.
- D'Aprile, Shane (May 9, 2011). "Missouri Republican Ed Martin shifts to House race instead of Senate bid". The Hill. Retrieved May 9, 2011.
- "Wagner Moves Toward Bid for Akin's Seat in Missouri : Roll Call Politics". Rollcall.com. April 26, 2011. Retrieved May 13, 2011.
- Johnson, Charles S. (July 17, 2010). "Horse Sense: Schweitzer not eyeing Senate seat". Billings Gazette.
- Johnson, Charles S. (February 5, 2011). "It's official: Rehberg says he's taking on Tester". Billings Gazette. Retrieved February 5, 2011.
- Adams, John S. (November 21, 2010). "Tester high on national GOP's hit list, observers say". Great Falls Tribune. Retrieved November 21, 2010.
- Blake, Aaron; Cillizza, Chris (February 27, 2012). "Bob Kerrey changes his mind, will run for Senate, source says". The Washington Post. Retrieved February 27, 2012.
- "Bruning 'ready to run' for Senate". Omaha.com. November 5, 2010.
- "Fischer begins U.S. Senate bid". The Omaha World-Herald. June 28, 2011.
- "Admission clouds Nevada Sen. John Ensign's future – Manu Raju and John Bresnahan and Alexander Burns". Politico.Com. Retrieved June 29, 2010.
- Mascaro, Lisa (July 14, 2009). "Ensign to stay in Senate, seek re-election". Las Vegas Sun. Retrieved July 14, 2009.
- Justin89119. "Text of Sen. John Ensign's resignation letter – Thursday, April 21, 2011 | 3:51 pm". Las Vegas Sun. Retrieved May 13, 2011.
- Catanese, David (April 27, 2011). "Sandoval appoints Heller – David Catanese". Politico.Com. Retrieved May 13, 2011.
- Witkowski, Wallace (February 18, 2011). February 2011 "Democrat Sen. Bingaman to retire in 2012: AP" Check
|url=scheme (help). marketwatch.com. Retrieved February 18, 2011.
- "Wilson formally enters U.S. Senate race". nmpolitics.net. March 7, 2011. Retrieved March 7, 2011.
- "Gillibrand has $10.5M in reelection bid". Wivb.com. LIN Television Corporation. July 16, 2012. Retrieved August 16, 2012.
- "New York Congressional Primaries Election Results". The New York Times. Retrieved August 16, 2012.
- Shaun Marie (June 27, 2012). "Congratulations Wendy Long!". Retrieved August 16, 2012.
- Haga, Chuck (January 18, 2011). "Conrad will not run for re-election in 2012". Grand Forks Herald. Retrieved January 18, 2011.
- Beitsch, rebecca (May 11, 2011). "Rep. Rick Berg to announce Senate run". Bismarcktribune.com. Retrieved June 27, 2011.
- "Kalk to Run for House Instead of Senate in North Dakota : Roll Call Politics". Rollcall.com. Retrieved June 27, 2011.
- Kate Nocera (November 7, 2012). "Heidi Heitkamp scores upset win in North Dakota". Politico. Retrieved April 17, 2014.
- Troyblade, Tom. "Politics". Toledo Blade. Retrieved May 13, 2011.
- "Mellow Casey has to up profile for re-election". The Morning Call. November 21, 2010.
- Davis, Michael (December 12, 2006). "Corker sets up re-election panel 1 day after win. Action called necessary for 'full-time job' of fundraising.". Chattanooga Times Free Press. Tenn. Knight Ridder Tribune Business News. (subscription)
- "Hank Williams Jr. Announces Senate Run – Politics News Story – WSMV Nashville". Wsmv.com. November 21, 2008. Retrieved June 29, 2010.
- "Hutchison may leave U.S. Senate in 2009 | Houston & Texas News | Chron.com – Houston Chronicle". Houston Chronicle. October 16, 2007. Retrieved June 29, 2010.
- "Hutchison won't give up Texas Senate seat - Politics - Decision 2010". MSNBC. March 31, 2010. Retrieved June 29, 2010.
- Feibel, Carolyn (December 17, 2008). "White announces Senate campaign via Web video". Houston Chronicle. Retrieved June 29, 2010.
- "?".[dead link]
- Watson, Brad (February 25, 2011). "Leppert says he is running for U.S. Senate". WFAA-TV. Retrieved February 25, 2011.
- "Hatch vows to run for re-election in 2012". The Hill.
- "Rep. Chaffetz Launches Statewide Campaign Tour".
- "GOP Senator Forced Into Primary Fight". Huffington Post. April 21, 2012.
- Camia, Catalina (February 9, 2011). "Sen. Jim Webb won't run for re-election in 2010". USA Today. Retrieved February 9, 2011.
- Catanese, David (January 24, 2011). "Allen e-mails supporters; Webb reacts". Politico. Retrieved January 30, 2011.
- "Virginia gets a Tea Party challenger". Politicalticker.blogs.cnn.com. December 29, 2010. Retrieved February 14, 2011.
- West Virginia Secretary of State "Candidate Search," Accessed January 29, 2012
- Kleefeld, Eric (May 13, 2011). "Wis. Dem Chair: Russ Feingold, Tammy Baldwin Could Run For Senate Seat". TPMDC. Retrieved May 13, 2011.
- Wenzel, Patti (May 13, 2011). "Senator Herb Kohl to retire after current term". ThirdCoast Digest. Retrieved May 13, 2011.