The 2012 United States Senate elections were held on November 6, 2012, with 33 of the 100 seats in the Senate, all Class 1 seats, being contested in regular elections whose winners would serve 6-year terms beginning on January 3, 2013, with the 113th Congress. Democrats had 21 seats up for election, plus 1 independent, and 1 independent Democrat, while the Republicans only had ten seats up for election. The presidential election, elections to the House of Representatives, elections for governors in 14 states and territories, and many state and local elections were also held on the same day.
The Democrats gained Republican-held seats in Massachusetts and Indiana and one from an Independent Democrat in Connecticut, leaving them with a total of 53 seats. Additionally, they held open seats in Hawaii, New Mexico, North Dakota, Virginia, and Wisconsin. The Republicans, despite losing 2 of their seats, picked an open seat in Nebraska up and retained open seats in Arizona and Texas, ending with a total of 45 seats. The Independents retained a seat in Vermont and gained an additional seat from the Republicans in Maine, bringing their total to 2 seats. Both Independents would caucus with the Democrats, forming a majority caucus with a combined total of 55 seats.
, this was the last time the Democrats won seats in Florida, Indiana, Missouri, and North Dakota. It was also the last time the Republican Party won a seat in Nevada. The Democrats would not win control of the Senate again until 2020 and would not win an outright majority again until 2022.
Additionally, this was the first time since 1936 that a 2-term Democratic presidential candidate had Senate coattails on both occasions. This was also the first time since 1964 (and the last time as of 2026) in which either party had to defend more than two-thirds of the Senate seats up for grabs but managed to make net gains. Furthermore, this was the last time the Republicans or either party won less than 10 Senate seats in a single election cycle, and the last time either party flipped a Senate seat in a presidential election year without carrying the state in the concurrent presidential election.
Results summary + ↓ 53 2 45 Democratic Independent Republican
Shading indicates party with largest share of that line. Parties Total Democratic Republican Libertarian Independence Green Others Before these elections 51 47 2 — — — — 100 Not up 30 37 — — — — — 67 20 13 — — — — — 33 10 24 — — — — — 34 Up 21 10 2 — — — — 33 21 10 2 — — — — 33 Incumbent retired 6 3 1 — — — — 10 5 2 — — — — — 7 1 Independent replaced by 1 Democrat 1 Republican replaced by 1 Independent 1 Democrat replaced by 1 Republican — — — — 3 6 3 1 — — — — 10 Incumbent ran 15 7 1 — — — — 23 15 5 1 — — — — 21 1 Republican replaced by 1 Democrat — — — — — 1 — — — — — — — 1 Republican replaced by 1 Democrat — — — — — 1 17 5 1 — — — — 23 Total elected 23 8 2 — — — — 33 Net gain/loss 2 2 — — — — 2 Nationwide vote 49,988,282 39,128,301 961,284 956,745 211,794 195,200 2,119,714 93,561,320 Share 53.43% 41.82% 1.03% 1.02% 0.23% 0.21% 2.27% 100% Result 53 45 2 — — — — 100 End of this Congress 51 47 2 — — — — 100
Change in composition
Before the elections D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D Majority → D R R R R R R R I I R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R
After the elections
D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D Majority → D R R R R R I I D D R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R Key: D Democratic I Independent R Republican
Race summary
Special elections during the 112th Congress There were no special elections during the 112th Congress.
Elections leading to the next Congress In these elections, the winners were elected for the term beginning January 3, 2013; ordered by state.
All of the elections involved the Class 1 seats.
State Incumbent Results CandidatesMultiple sources:
Senator Party Electoral history Arizona Republican 199420002006 Incumbent retired.Republican hold. California Democratic 1992 199420002006 Incumbent re-elected. Connecticut IndependentDemocrat 1988199420002006 Incumbent retired.Democratic gain. Delaware Democratic 20002006 Incumbent re-elected. Florida Democratic 20002006 Incumbent re-elected. Hawaii Democratic 1990 1990 199420002006 Incumbent retired.Democratic hold. Indiana Republican 197619821988199420002006 Incumbent lost renomination. Democratic gain. Maine Republican 199420002006 Incumbent retired.Independent gain. Maryland Democratic 2006 Incumbent re-elected. Massachusetts Republican 2010 Incumbent lost re-election.Democratic gain. Michigan Democratic 20002006 Incumbent re-elected. Minnesota DFL 2006 Incumbent re-elected. Mississippi Republican 2007 2008 Incumbent re-elected. Missouri Democratic 2006 Incumbent re-elected. Montana Democratic 2006 Incumbent re-elected. Nebraska Democratic 20002006 Incumbent retired.Republican gain. Nevada Republican 2011 Interim appointee elected. New Jersey Democratic 2006 2006 Incumbent re-elected. New Mexico Democratic 19821988199420002006 Incumbent retired.Democratic hold. New York Democratic 2009 2010 Incumbent re-elected. North Dakota Democratic-NPL 19861992 ()1992 199420002006 Incumbent retired.Democratic-NPL hold. Ohio Democratic 2006 Incumbent re-elected. Pennsylvania Democratic 2006 Incumbent re-elected. Rhode Island Democratic 2006 Incumbent re-elected. Tennessee Republican 2006 Incumbent re-elected. Texas Kay Bailey Hutchison Republican 1993 199420002006 Incumbent retired.Republican hold. Utah Republican 197619821988199420002006 Incumbent re-elected. Vermont Independent 2006 Incumbent re-elected. Virginia Democratic 2006 Incumbent retired.Democratic hold. Washington Democratic 20002006 Incumbent re-elected. West Virginia Democratic 2010 Incumbent re-elected. Wisconsin Democratic 1988199420002006 Incumbent retired.New senator elected.Democratic hold. Wyoming Republican 2007 2008 Incumbent re-elected.
Closest races Elections with a margin less than 10.0%. District Winner Margin North Dakota Democratic 0.9% Nevada Republican 1.2% Arizona Republican 3.0% Montana Democratic 3.7% Wisconsin Democratic 5.5% New Mexico Democratic 5.7% Indiana Democratic (flip) 5.7% Virginia Democratic 5.9% Ohio Democratic 6.0% Massachusetts Democratic (flip) 7.5% Pennsylvania Democratic 9.1%
Final pre-election predictions The table below gives an overview of some final predictions of the November general elections by several well-known institutes and people. 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.
State Incumbent Lastelection Roll CallRoll Call Race Update Sabato CookCook Political Race Update RothenbergRothenberg Political Report Race Update RCPRCP Race Update 538FiveThirtyEight Race Update PrincetonPEC Race Update Winner Arizona Jon Kyl 53.3% R Flake49.2% R California Dianne Feinstein 59.4% D Feinstein62.5% D Connecticut Joe Lieberman 49.7% I Murphy54.8% D Delaware Tom Carper 67.1% D Carper64.2% D Florida Bill Nelson 60.3% D Nelson55.2% D Hawaii Daniel Akaka 61.4% D Hirono62.6% D Indiana Richard Lugar 87.3% R Donnelly50.0% D Maine Olympia Snowe 74.4% R King52.9% I Maryland Ben Cardin 54.2% D Cardin56.0% D Massachusetts Scott Brown 51.9% R Warren53.7% D Michigan Debbie Stabenow 56.9% D Stabenow58.8% D Minnesota Amy Klobuchar 58.1% D Klobuchar65.2% D Mississippi Roger Wicker 55.0% R Wicker57.2% R Missouri Claire McCaskill 49.6% D McCaskill54.8% D Montana Jon Tester 49.2% D Tester48.6% D Nebraska Ben Nelson 63.9% D Fischer57.8% R Nevada Dean Heller Appointed Heller45.9% R New Jersey Bob Menendez 53.4% D Menendez58.9% D New Mexico Jeff Bingaman 70.6% D Heinrich51.0% D New York Kirsten Gillibrand 59.6% D Gillibrand71.6% D North Dakota Kent Conrad 68.8% D Heitkamp50.24% D Ohio Sherrod Brown 56.2% D Brown50.7% D Pennsylvania Bob Casey Jr. 58.7% D Casey53.7% D Rhode Island Sheldon Whitehouse 53.5% D Whitehouse64.8% D Tennessee Bob Corker 50.7% R Corker64.9% R Texas Kay Bailey Hutchison 61.7% R Cruz56.5% R Utah Orrin Hatch 62.6% R Hatch65.3% R Vermont Bernie Sanders 65.4% I Sanders71% I Virginia Jim Webb 49.6% D Kaine52.9% D Washington Maria Cantwell 56.9% D Cantwell60.5% D West Virginia Joe Manchin 53.5% D Manchin60.6% D Wisconsin Herb Kohl 67.3% D Baldwin51.4% D Wyoming John Barrasso 73.4% R Barrasso75.7% R
Gains and losses
Retirements Six Democrats, one independent Democrat, and three Republicans retired instead of seeking re-election. StateSenator Age at end of term AssumedofficeReplaced by Arizona 70 1995 Connecticut 70 1989 Hawaii 88 1990 Maine 65 1995 Nebraska 71 2001 New Mexico 69 1983 North Dakota 64 1992 Texas 69 1993 Virginia 66 2007 Wisconsin 77 1989
Defeats Two Republicans sought re-election but lost in either the primary or general election.
StateSenatorAge atend of termAssumedofficeReplaced by Indiana 80 1977 Massachusetts 53 2010
Post-election changes One Democrat died before the start of the 113th Congress on December 17, 2012. One Democrat died during the 113th Congress on June 3, 2013. Two Democrats and one Republican resigned. All were replaced, at least initially, by appointees. In New Jersey and Massachusetts, special elections were held prior to the 2014 Senate elections for the remainder of the Class 2 terms, where Democrat Cory Booker won the New Jersey special election to succeed Republican appointee Jeffrey Chiesa, who did not seek election; and in Massachusetts, where Ed Markey won to succeed Democratic appointee Mo Cowan, who did not seek election. StateSenatorReplaced by Hawaii(Class 3) South Carolina(Class 3) Massachusetts(Class 2) New Jersey(Class 2) Massachusetts(Class 2) New Jersey(Class 2) Montana(Class 2)
Arizona
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.
Preliminary general election results showed Flake leading 49.7%-45.7%, but 439,961 early votes had yet to be counted. The official results, as tabulated by the secretary of state, showed a slightly smaller win for Flake. Flake won the election with 49.7% of the vote against Carmona's 46.2% and Victor's 4.6%.
California
Incumbent Democrat Dianne Feinstein was re-elected. The primary election on June 5 took place under California's new blanket primary, where all candidates appear on the same ballot, regardless of party. In the primary, voters voted for any candidate listed, or write-in any other candidate. The top two finishers — regardless of party — advanced to the general election in November, even if a candidate managed to receive a majority of the votes cast in the June primary. In the primary, less than 15% of the total 2010 census population voted. Incumbent Democrat Dianne Feinstein finished first in the blanket primary with 49.5% of the vote. The second-place finisher was Republican candidate and autism activist Elizabeth Emken, who won 12.7% of the vote.