The 2006 United States Senate election in Ohio was held on November 7, 2006. Incumbent Republican Mike DeWine ran for re-election, but was defeated by Democratic Congressman Sherrod Brown. As of , this is the most recent time a Democratic Senate candidate in Ohio won a race by double digits. This was also the last time an incumbent senator lost reelection in Ohio, until Brown was defeated in 2024 by Bernie Moreno.

To date, this is Mike DeWine's second general election loss of his political career, following his 1992 loss to John Glenn. Following his defeat, DeWine served as Ohio's state attorney general from 2011 to 2019, and has been the state's governor since 2019.

Background The incumbent Republican Senator R. Michael DeWine had approval ratings at 38%, making him the second most unpopular U.S. senator behind Pennsylvania Republican Rick Santorum, who was also up for reelection in 2006. Pre-election stories in the U.S. media suggested that the national Republican Party might have given up on saving Senator DeWine's Senate seat before election day. Sherrod Brown, former Ohio secretary of state and U.S. representative from Ohio's 13th district, easily won the Democratic nomination over Merrill Keiser Jr.

Republican primary Candidates Mike DeWine, incumbent U.S. senator since 1995 William G. Pierce, engineer David Smith, candidate for U.S. representative from Ohio's 2nd congressional district in 2005

Campaign Both candidates campaigned as conservative alternatives to DeWine, citing DeWine's support for gun control measures and his role as a member of the Gang of 14, a group of Republicans who compromised with Democrats in a dispute about judicial appointments.

Results

Democratic primary Candidates Declared Sherrod Brown, U.S. representative from Lorain Merrill Keiser Jr., trucking business owner/operator and Vietnam War veteran

Withdrew Paul Hackett, Iraq War veteran

Results

General election

Candidates Sherrod Brown, U.S. representative from Lorain (Democratic) Mike DeWine, incumbent senator since 1995 (Republican) Richard Duncan (Independent) (write-in)

Campaign The Republican Party, which was facing multiple challenges to their Senate majority, was initially determined to assist DeWine in his competitive race, while the National Democratic party supported Brown in hopes of taking control of the Senate. John McClelland, a spokesman for the Ohio Republican Party, said, "It's vitally important to the Republican Party as a whole, so I think that's why you see the president coming to Ohio to support Mike DeWine." Phil Singer, a spokesman for the Democratic Senatorial Campaign Committee, said, "Mike DeWine Senior is in for the fight of his life, make no mistake about it."

On July 14, 2006, DeWine's campaign began airing TV commercials depicting a smoking World Trade Center. "The senator was notified... by a reporter at U.S. News & World Report that the image of the burning Twin Towers could not have depicted the actual event because the smoke was blowing the wrong way."Nation & World: DeWine blunder adds fuel to controversial September 11 ad - U.S. News & World Report DeWine's campaign admitted that the video was actually a still photo of the World Trade Center with smoke digitally added. He was also criticized for using an emotionally charged image to attack his challenger.

Another of DeWine's ads suggested that opponent Sherrod Brown did not pay his taxes for thirteen years. This claim led to the Associated Press reporting on October 19 that "Several Ohio television stations have stopped airing a Republican ad because state documents contradict the ad's accusation that Democratic U.S. Senate candidate Sherrod Brown didn't pay an unemployment tax bill for 13 years." Brown produced a commercial citing these facts. DeWine's ads were changed to state only that he had failed to pay his unemployment taxes until legal action was taken against him.

On October 16, 2006, The New York Times reported that top national Republicans were moving resources away from the Ohio Senate race, as they had determined that DeWine was likely to lose, and wanted to spend money on races where Republican candidates were seen as having a better chance of winning.Adam Nagourney, "In Final Weeks, G.O.P. Focuses on Best Bets", The New York Times, October 16, 2006.

Debates Complete video of debate, October 1, 2006 Complete video of debate, October 13, 2006 Complete video of debate, October 19, 2006 Complete video of debate, October 27, 2006

Fundraising During the election cycle, DeWine raised $14.9 million and spent $15.5 million. Brown raised $8.9 million and spent $10.8 million.

Predictions Source Ranking As of The Cook Political Report November 6, 2006 Sabato's Crystal Ball November 6, 2006 Rothenberg Political Report November 6, 2006 Real Clear Politics November 6, 2006

Polling Source Date SherrodBrown (D) MikeDeWine (R)ZogbyZogby October 31, 2005 40% 37%RasmussenRasmussen December 2, 2005 41% 43%RasmussenRasmussen January 7, 2006 40% 45%RasmussenRasmussen February 18, 2006 37% 46%RasmussenRasmussen March 31, 2006 42% 45%Zogby/WSJZogby/WSJ March 31, 2006 46% 37%RasmussenRasmussen April 24, 2006 41% 43%Mason-DixonMason-Dixon April 26, 2006 36% 47%RasmussenRasmussen May 15, 2006 44% 41%University of CincinnatiUniversity of Cincinnati May 25, 2006 42% 52%Survey USASurvey USA June 13, 2006 48% 39%Zogby/WSJ June 21, 2006 47% 34%RasmussenRasmussen June 27, 2006 39% 46%Columbus DispatchColumbus Dispatch July 23, 2006 45% 37%Zogby/WSJ July 24, 2006 45% 37%RasmussenRasmussen August 1, 2006 44% 42%SurveyUSASurveyUSA August 5, 2006 49% 41%RasmussenRasmussen August 26, 2006 45% 42%Zogby/WSJZogby/WSJ August 28, 2006 47% 39%GallupGallup September 5, 2006 46% 40%Zogby/WSJ September 11, 2006 45% 41%RasmussenRasmussen September 13, 2006 47% 41%QuinnipiacQuinnipiac September 20, 2006 45% 44%University of CincinnatiUniversity of Cincinnati September 20, 2006 51% 47%SurveyUSASurveyUSA September 21, 2006 52% 42%Columbus DispatchColumbus Dispatch September 24, 2006 47% 42%Zogby/WSJ September 28, 2006 45% 41%University of AkronUniversity of Akron September 29, 2006 42% 42%Mason-DixonMason-Dixon October 1, 2006 45% 43%Reuters/ZogbyReuters/Zogby October 5, 2006 41% 41%RasmussenRasmussen October 5, 2006 49% 41%SurveyUSASurveyUSA October 12, 2006 54% 40%RasmussenRasmussen October 13, 2006 48% 42%QuinnipiacQuinnipiac October 17, 2006 53% 41%University of CincinnatiUniversity of Cincinnati October 17, 2006 52% 45%CBS News/New York TimesCBS News/New York Times October 17, 2006 49% 35%Mason-Dixon/MSNBCMason-Dixon/MSNBC October 24, 2006 48% 40%Los Angeles Times/BloombergLos Angeles Times/Bloomberg October 24, 2006 47% 39%RasmussenRasmussen October 26, 2006 53% 41%SurveyUSASurveyUSA October 26, 2006 57% 37%Opinion ConsultantsOpinion Consultants October 22–30, 2006 51% 44%CNN/Opinion Research CorporationCNN/Opinion Research Corporation October 31, 2006 54% 43%Reuters/Zogby InternationalReuters/Zogby International November 2, 2006 56% 42%RasmussenRasmussen November 4, 2006 54% 43%Mason-Dixon/MSNBC-McClatchyMason-Dixon/MSNBC-McClatchy November 5, 2006 50% 44%Columbus DispatchColumbus Dispatch November 5, 2006 62% 38%University of Cincinnati Ohio PollUniversity of Cincinnati Ohio Poll November 6, 2006 56% 44%SurveyUSASurveyUSA November 6, 2006 54% 42%

Results Brown was declared the winner right when the polls closed in Ohio at 7:30. DeWine had the second worst performance of a Republican incumbent in 2006; only Pennsylvania Senator Rick Santorum had a worse performance. While DeWine was able to win rural counties in western Ohio, Brown managed to win most eastern Ohio counties, especially in heavily populated areas. DeWine's narrow 2,000 vote victory in Hamilton County, which is home to Cincinnati, did not come close to making a dent in Brown's lead.

Brown would be reelected to a second term in 2012, and a third term in 2018. Also in 2018, both Brown and DeWine were on the ballot, but this time for different races; DeWine would be elected governor of Ohio. In 2024, Brown would be defeated for reelection.

By county