Skip to content

2004 U.S. Senate election results

Results of all 34 Senate races in 2004 (seats won: Republican 19, Democratic 15); 8 changed party. Winners, margins and every candidate.

Download CSV
  • Republican 19
  • Democratic 15
Alabama: Richard C. Shelby REP +35.2Alaska: Lisa Murkowski REP +3.0Arizona: John McCain REP +56.1Arkansas: Blanche Lincoln DEM +11.8California: Barbara Boxer DEM +19.9Colorado: Ken Salazar DEM +4.8 gainConnecticut: Christopher J. Dodd DEM +34.2DelawareDistrict of ColumbiaFlorida: Mel Martinez REP +1.1 gainGeorgia: Johnny Isakson REP +17.9 gainHawaii: Daniel K. Inouye DEM +54.5Idaho: Mike Crapo REP +98.4Illinois: Barack Obama DEM +42.9 gainIndiana: Evan Bayh DEM +24.4Iowa: Chuck Grassley REP +42.3Kansas: Sam Brownback REP +41.7Kentucky: Jim Bunning REP +1.3Louisiana: David Vitter REP +21.7 gainMaineMaryland: Barbara A. Mikulski DEM +31.1MassachusettsMichiganMinnesotaMississippiMissouri: Christopher S. Bond REP +13.3MontanaNebraskaNevada: Harry Reid DEM +25.9New Hampshire: Judd Gregg REP +32.5New JerseyNew MexicoNew York: Charles E. Schumer DEM +37.1North Carolina: Richard Burr REP +4.6 gainNorth Dakota: Byron L. Dorgan DEM +36.6Ohio: George V. Voinovich REP +27.7Oklahoma: Tom Coburn REP +11.5Oregon: Ron Wyden DEM +31.7Pennsylvania: Arlen Specter REP +10.6Rhode IslandSouth Carolina: Jim DeMint REP +9.6 gainSouth Dakota: John R. Thune REP +1.2 gainTennesseeTexasUtah: Robert F. Bennett REP +40.3Vermont: Patrick J. Leahy DEM +46.1VirginiaWashington: Patty Murray DEM +12.2West VirginiaWisconsin: Russ Feingold DEM +11.2WyomingVermont: Patrick J. Leahy DEM +46.1New Hampshire: Judd Gregg REP +32.5MassachusettsRhode IslandConnecticut: Christopher J. Dodd DEM +34.2New JerseyDelawareMaryland: Barbara A. Mikulski DEM +31.1District of Columbia
States with a race in 2004, coloured by the winning party and shaded by margin. Grey: no race.

Seats that changed party

All races

StateSeatWinnerPartyMarginBefore
Alabama Class III Richard C. Shelby Republican 35.2 Republican
Alaska Class III Lisa Murkowski Republican 3.0 Republican
Arizona Class III John McCain Republican 56.1 Republican
Arkansas Class III Blanche Lincoln Democratic 11.8 Democratic
California Class III Barbara Boxer Democratic 19.9 Democratic
Colorado Class III Ken Salazar Democratic 4.8 Republican flip
Connecticut Class III Christopher J. Dodd Democratic 34.2 Democratic
Florida Class III Mel Martinez Republican 1.1 Democratic flip
Georgia Class III Johnny Isakson Republican 17.9 Democratic flip
Hawaii Class III Daniel K. Inouye Democratic 54.5 Democratic
Idaho Class III Mike Crapo Republican 98.4 Republican
Illinois Class III Barack Obama Democratic 42.9 Republican flip
Indiana Class III Evan Bayh Democratic 24.4 Democratic
Iowa Class III Chuck Grassley Republican 42.3 Republican
Kansas Class III Sam Brownback Republican 41.7 Republican
Kentucky Class III Jim Bunning Republican 1.3 Republican
Louisiana Class III David Vitter Republican 21.7 Democratic flip
Maryland Class III Barbara A. Mikulski Democratic 31.1 Democratic
Missouri Class III Christopher S. Bond Republican 13.3 Republican
Nevada Class III Harry Reid Democratic 25.9 Democratic
New Hampshire Class III Judd Gregg Republican 32.5 Republican
New York Class III Charles E. Schumer Democratic 37.1 Democratic
North Carolina Class III Richard Burr Republican 4.6 Democratic flip
North Dakota Class III Byron L. Dorgan Democratic 36.6 Democratic
Ohio Class III George V. Voinovich Republican 27.7 Republican
Oklahoma Class III Tom Coburn Republican 11.5 Republican
Oregon Class III Ron Wyden Democratic 31.7 Democratic
Pennsylvania Class III Arlen Specter Republican 10.6 Republican
South Carolina Class III Jim DeMint Republican 9.6 Democratic flip
South Dakota Class III John R. Thune Republican 1.2 Democratic flip
Utah Class III Robert F. Bennett Republican 40.3 Republican
Vermont Class III Patrick J. Leahy Democratic 46.1 Democratic
Washington Class III Patty Murray Democratic 12.2 Democratic
Wisconsin Class III Russ Feingold Democratic 11.2 Democratic

Source: FiveThirtyEight election-results; each race page links the official source it was compiled from.