Senate Races 2010 Header Graphic
Balance before was 57 Democrats, 41 Republicans, 2 Independents.
37 seats at stake:19 held by Democrats and 18 by Republicans.
15 open seats of which 7 held by Democrats and 8 held by Republicans.
12 retirements, 3 defeated in primary.*
Of 23 sitting Senators seeking re-election or election on Nov. 2, 21 succeeded.
16 new Senators were elected (although 1 had previously served).
Republicans won 23 (24)* seats, Democrats 13 seats.
Balance after is 51 Democrats, 47 Republicans, 2 Independents.

*Sen. Murkowski (R-AK) lost the primary, but won as a write-in.

Updated November 16, 2010.
There was some talk that Republicans might have a chance of gaining control of the Senate
but, in the view of many observers, wins by several Tea Party backed candidates over more centrist candidates in the primaries cost them that opportunity.  A relatively high 15 open seats were at stake on November 2 (compare to seven in 2002, seven in 2004, four in 2006 and six in 2008).  In part this was due to the large number of appointed Senators in the 111th Congress, a total of seven.  Sens. Michael Bennet (D-CO), Ted Kaufman (D-DE), Raymond Burris (D-IL)1 and Kirsten Gillibrand (D-NY) resulted from Obama appointments.  Following the death of Sen. Ted Kennedy (D-MA), Gov. Deval Patrick appointed Paul Kirk (D); Kirk served until the Jan. 19, 2010 special election resulted in the election of Scott Brown (R).  In Florida after the resignation of Sen. Mel Martinez (R), Gov. Charlie Crist (R) appointed George LeMieux (R).  Following the death of Sen. Robert Byrd (D-WV) on June 28, Gov. Joe Manchin (D) on July 16 named attorney Carte P. Goodwin to fill the position on an interim basis.2  Of the appointed Senators only Bennet and Gillibrand sought election and both succeeded.  Three open seats were due to incumbents who lost during the primary season: Bennett (R-UT) was defeated at the state party convention on May 8, Specter (D-PA) lost in the May 18 primary and Murkowski (R-AK) was upset in the Aug. 24 primary.  Tea Party backed candidates achieved significant upsets in primaries around the country, starting with Rand Paul's win in Kentucky, continuing to Sharron Angle in Nevada, Mike Lee in Utah, Ken Buck in Colorado, Joe Miller in Alaska, and finally Christine O'Donnell in Delaware.  Probably the most watched Senate race in the country was in Nevada where Senate Majority Leader Harry Reid (D) faced a surprisingly strong challenge from Sharron Angle (R).  Money was of course a factor; the Center for Responsive Politics reported that on average in 2008, winning U.S. Senate candidates spent more than twice as much as losing ones: $8.5 million to $4.1 million.  Three of the newly elected Senators are being seated in the lame duck session: Coons (D-DE), Manchin (D-WV) and Kirk (R-IL).
Committees: DSCC (finances) | NRSC (finances). 
Finances: FEC 2010 House and Senate Campaign Finance,
Open Secrets.
Press, Pundits and Prognosticators:
CQ Politics, Cook Political Report, Sabato's Crystal Ball.
By Party: D  | R
  | L  | G  | C  | O/I.

Winners in bold; not every third party and independent candidates is shown.

May 18
Blanche Lincoln (won June 8 runoff)
Rep. John Boozman
John L. Gray (G)
June 8
Barbara Boxer
former Hewlett-Packard CEO Carly Fiorina
Edward C. Noonan (AIP)
Duane Roberts (G)
Gail K. Lightfoot (L)
Marsha Feinland (P&F)
Aug. 10
Michael Bennet

Weld County district attorney Ken Buck
Bob Kinsey (G)
Maclyn Stringer (L)
Aug. 10
*[Chris Dodd (retiring 01/06/10)]
AG Richard Blumenthal
former World Wrestling Entertainment CEO Linda McMahon 
John Mertens (CFL)
Warren Mosler (IP)
Sept. 14
*[Ted Kaufman (retiring)]
Chris Coons
marketing consultant Christine O'Donnell
Jim Rash (L)
Sept. 18
Dan Inouye
Cam Cavasso
Jeff Mallan (L)
Jeff Jarrett (I)
Feb. 2
*[Roland Burris (retiring)]
Treas. Alexi Giannoulias
Rep. Mark Kirk
Randy Stufflebeam (C)
LeAlan Jones (G)
Mike Labno (L)
May 4
*[Evan Bayh (retiring 02/15/10)]
Rep. Brad Ellsworth
former Sen. Dan Coats
Rebecca Sink-Burris (L)
Sept. 14
Barbara Mikulski
physician/County Commissioner Eric Wargotz
Natasha Pettigrew (G) replaced by Kenniss Henry (G)
June 8
Harry Reid
former Assemblywoman Sharron Angle
Scott Ashjian (Tea)
Tim Fasano (IAP)
Jesse Holland (I)
Jeffrey Reeves (I)
Sept. 14
Chuck Schumer
political strategist Jay Townsend (R/C)
Colia Clark (G)
Randy Credico (L)
Sept. 14
Kirsten Gillibrand
former Rep. Joe DioGuardi (R/C)
Cecile Lawrence (G)
June 8
*[Byron Dorgan (retiring 01/05/10)]
state Sen. Tracy Potter
Gov. John Hoeven Keith Hanson (L)
May 18
Ron Wyden
law professor Jim Huffman
Rick Staggenborg
Marc Delphine (L)
May 18
*[Arlen Specter (defeated in primary)]
Rep. Joe Sestak
former Rep. Pat Toomey
Aug. 24
Pat Leahy
lumber store owner Len Britton
Stephen J. Cain (I)
Peter Diamondstone (LU)
Chris Ericson (USMJ)
Daniel Freilich (I)
Johenry Nunes (I)
Rick Russell (WF)
Aug. 17
Patty Murray
former state Sen. Dino Rossi

Aug. 28
*[Robert Byrd (died June 28)]
Gov. Joe Manchin
industrialist John Raese Jesse Johnson (MP)
Jeff Becker (C)
Sept. 14
Russ Feingold
Ron Johnson
Rob Taylor (C)

June 1
attorney William Barnes
Richard Shelby
Aug. 24
Sitka Mayor Scott McAdams
*[Lisa Murkowski (defeated in primary)]
attorney Joe Miller
Sen. Lisa Murkowski (w/in)
David Haase (L)
Tim Carter (pet.)
Ted Gianoutsos (pet.)
Aug. 24
Tucson City Councilman Rodney Glassman
John McCain
Jerry Joslyn (G)
David F. Nolan (L)
Aug. 24
Rep. Kendrick Meek
*[George LeMieux (retiring)]
former Speaker Marco Rubio
Gov. Charlie Crist (I)
Bernie DeCastro (C)
Alex Snitker (L)
July 20
Labor Comm. Mike Thurmond
Johnny Isakson
Chuck Donovan (L)
May 25
business owner Tom Sullivan
Mike Crapo
Randy Bergquist (C)
June 8
attorney Roxanne Conlin
Chuck Grassley
John Heiderscheit (L)
May 18
AG Jack Conway
*[Jim Bunning (retiring 07/27/09)]
Rand Paul
John Long (I)
Aug. 3
Baker University assistant dean Lisa Johnston *[Sam Brownback (running for Gov.)]
Rep. Jerry Moran
Mike Dann (L)
Joe Bellis (Ref.)
Aug. 28
Rep. Charlie Melancon
David Vitter

Randall Hayes (L)
William McShan (Ref.)

Mike Spears (I)
State Rep. Ernest Wooton (I)
Aug. 3
Sec. of State Robin Carnahan
*[Kit Bond (retiring 01/08/09)]
Rep. Roy Blunt
Jerry Beck (C)
Jonathan Dine (L)
Sept. 14
Rep. Paul Hodes
*[Judd Gregg (retiring 02/13/09)]
former AG Kelly Ayotte
Ken Blevens (L)
several independents
May 4
Sec. of State Elaine Marshall (won June 22 runoff)

Richard Burr
Mike Beitler (L)
Richard Weir (G-w/in)
May 4
Lt. Gov. Lee Fisher
*[George Voinovich (retiring 01/12/09)]
former Rep. Rob Portman
Eric Deaton (C)
Dan LaBotz (S)
July 27
retired schoolteacher Jim Rogers
Tom Coburn
Steve Wallace (I)
Ronald Dwyer (I)
June 8
unemployed veteran Alvin Greene
Jim DeMint
Tom Clements (G)
June 8
no challenger
John Thune
June 22
restauranteur Sam Granato
*[Bob Bennett (defeated at Convention on May 8)]
attorney Mike Lee
Scott Bradley (C)
1. The situation in Illinois grew a bit more messy in summer 2010, when a court ruled that Burris' appointment was temporary, necessitating that a special election be held to fill the final two months of the term. 
The West Virginia legislature set a primary for Aug. 28 and a special election coinciding with the November 2 general election (1, 2, 3, 4).

IL Feb. 2

IN May 4
AR May 18
ID May 25
AL June 1
CA June 8
June 22
GA July 20
OK July 27
KS Aug. 3
CO Aug. 10
WA Aug. 17
AK Aug. 24
LA Aug. 28
DE Sept. 14
HI Sept. 18

An Overview of Interesting Primaries
Sept. 14

DE GOP: In one of the biggest upsets of the cycle, Tea Party-backed marketing consultant Christine O'Donnell defeated nine-term congressman and former governor Mike Castle.  O'Donnell depicted the moderate Castle, who was backed by the Republican Party, as a RINO.

MD GOP: Queen Anne's County Commissioner Eric Wargotz, a physician, finished first out of a field of 11 candidates with about 38.7%; Tea Party backed attorney Jim Rutledge finished second with about 31.4%.

NH GOP: Former Attorney General Kelly Ayotte was the early favorite in a field of seven candidates, but toward the close of the race attorney Ovide Lamontagne surged to make it very close ultimately finishing 1,678 votes back; others in the race included businessmen Bill Binnie and Jim Bender.

Political strategist Jay Townsend (R/C) bested retired CIA officer Gary Berntsen in the race for the Shumer seat, and former Rep. Joe DioGuardi (R/C) finished ahead of economist David Malpass and attorney Bruce Blakeman to challenge for the Gillibrand seat.
Aug. 28

LA GOP: Sen. David Vitter weathered the 2007 prostitution scandal and revelations over a staffer to resoundingly win the primary former state Supreme Court Associate Justice Chet Taylor.

WV GOP: A total of fourteen candidates were on the ballot including nine Republicans.  Greer Industries president and CEO John Raese finished with four times as many votes as the next closest Republican "Mac" Warner.
Aug. 24
AZ DEM: Tucson City Councilman Rodney Glassman finished first out a field of four little known candidates.

FL DEM: Rep. Kendrick Meek won with 55% of the vote; billionaire Jeff Greene made it a race before fading; he obtained 33%.  Natural health educator Glenn Burkett finished with 7% and former Miami Mayor Maurice Ferrre obtained 5%.
AK GOP: Attorney Joe Miller, who was backed by former Gov. Sarah Palin and former Gov. Mike Huckabee, upset Sen. Lisa Murkowski , who conceded on Aug. 31. >

AZ GOP: This race drew a lot of attention, but Sen. John McCain ran an aggressive campaign, spending over $20 million to defeat Tea Party backed former Rep. J.D. Hayworth by 56% to 32% with 11% for Jim Deakin.

FL GOP: Gov. Charlie Crist's
announcement on April 29, 2010 that he would leave the Republican Party and run as an Independent left the field largely clear for former House Speaker Marco Rubio, a Tea Party favorite who has attracted national attention; he easily dispatched a couple of very longshot candidates in the primary.
Aug. 17

WA GOP: Under Washington's Top 2 Primary, 15 candidates appeared on the ballot (the top two move on to the general election). Sen. Murray (D) finished first with 46.2% and former state Sen. Dino Rossi (R), the 2004 and 2008 gubernatorial nominee, finished second with 34.0%.  Former pro football player and farmer Clint Didier, who was backed by the Tea Party and Sarah Palin, fell short, obtaining 11.9%.
Aug. 10
CO DEM: Former Speaker of the House Andrew Romanoff sold his house in his effort to defeat appointed Sen. Michael Bennet; Romanoff was also endorsed by Bill Clinton, but Bennet carried the day by a 54% to 46% margin.
CO GOP: The closely fought race between former Lt. Gov. Jane Norton and Weld County district attorney Ken Buck resulted in a 51.5% to 48.4% win for Buck.

Former World Wrestling Entertainment CEO Linda McMahon, who won the endorsement of the GOP Convention on May 21, won the primary with about 49%. Former Rep. Rob Simmons scaled back/suspended his campaign, but remained on the ballot, and in July resumed some activity; he finished second with about 28%.  Businessman and author Peter Schiff, who remained active throughout, was third with about 23%.
Aug. 3
KS DEM: In a race among five candidates, Baker University assistant dean Lisa Johnston finished with 31% to 24% for the much more experienced communications executive Charles Schollenberger, 19% for state Sen. David Haley, 16% for Patrick Weisner and 10% Robert A. Conroy.
KS GOP: In the bitterly contested race between Rep. Jerry Moran and Rep. Todd Tiahrt, Moran finished ahead by a 50% to 45% margin.
June 22
NC DEM runoff: Sec. of State Elaine Marshall defeated former State Sen. Cal Cunninghamg by 60% to 40%.  Marshall gained the backing of third place finisher Kevin Lewis; Cunningham had the backing of national Democrats. UT GOP: Although businessman Tim Bridgewater finished first with 57% at the May 8 Utah Republican Convention, attorney Mike Lee  carried the day on June 22 with a 51% to 49% win.
June 8
SC DEM: Despite waging no campaign, unknown unemployed veteran Alvin Greene upset Charleston County Councilman and former legislator Vic Rawl. Many questions were raised about Greene and his campaign, and his win was attributed to his being the first name that appeared. The South Carolina Democratic Party rejected a protest by Rawl. > Subsequently a group of Democrats started a petition effort to get Linda Ketner on the ballot as an independent; however, Ketner announced on July 5 that she would not accept a petition candidacy.

AR DEM runoff: Sen. Blanche Lincoln defied expectations to defeat Lt. Gov.
Bill Halter.
CA GOP: Former Hewlett-Packard CEO Carly Fiorina defeated former Rep. Tom Campbell and Assemblyman Chuck DeVore.  The Fiorina campaign reported $7.4 million in receipts of which $3.6 million came from the candidate, compared to $2.6 million in receipts for Campbell and $2.3 million for DeVore.

NV GOP: Twelve candidates competed for the nomination.  Tea Party backed former Assemblywoman Sharron Angle defeated former state party chair Sue Lowden, and realtor, basketballer, and 2006 Sec. of State candidate Danny Tarkanian.
May 18
AR DEM: Lt. Gov. Bill Halter received a lot of support from outside progressive groups and organized labor and forced Sen. Blanche Lincoln. to a June 8 run-off.  Lincoln received 44.5%  to 42.5% for Halter and 13% for businessman D.C. Morrison.

The Republican primary attracted considerably more attention but the Democratic race proved to be a squeaker, as AG Jack Conway defeated Lt. Gov. Dan Mongiardo by less than 4,000 votes, 44% to 43%

Five-term Republican Sen. Arlen Specter switched to the Democratic party in April 2009 and was embraced by the Democratic establishment; Rep.
Joe Sestak was not dissuaded from running and won amid low turnout, defeating the 80-year old incumbent by 54% to 46%.
AR GOP: Five-term Rep. John Boozman finished first in a field of eight candidates with about 52%; the nearest runner up was Jim Holt at 17%.

With the support of tea party activists, Rand Paul won by a surprising 59% to 35% margin over Sec. of State Trey Grayson. Grayson had been backed by Senate Majority Leader Mitch McConnell.  +
May 15
IN DEM: State Democratic Committee formally selected Rep. Brad Ellsworth as the nominee on May 15.
May 8

UT GOP: Sen. Bob Bennett was defeated at the Utah Republican Convention; June 22 primary between businessman Tim Bridgewater and attorney Mike Lee.
May 4
OH DEM: Lt. Gov. Lee Fisher defeated Sec. of State Jennifer Brunner by 56% to 44%.

NC DEM: Sec. of State Elaine Marshall and former State Sen. Cal Cunningham are in a June 22 runoff; Marshall obtained 36.4% to 27.2% for Cunninghan and 17.1% for attorney Ken Lewis.
IN GOP: Former Sen. Dan Coats bested state Sen., farmer, and small businessman Marlin A. Stutzman and former Rep. John N. Hostettler by 39% to 30% and 22% with the remainder going to two others.
Feb. 2
IL DEM: Treasurer Alexi Giannoulias defeated former Chicago Inspector General David Hoffman and Chicago Urban League President Cheryle Jackson by 38.7% to 33.5% and 19.7%.