2006 United States Senate election in Ohio

• Sherrod Brown, U.S. Representative
• Merrill Keiser Jr., trucking business owner/operator and Vietnam veteran

• Paul Hackett, Iraq War veteran

Hackett announced on February 13, 2006 that he would withdraw from the race, because national party leaders had decided that Sherrod Brown had a better chance against DeWine. The Plain Dealer (2/18/06) also reported that there had been concerns that Hackett might not have had enough money after the primary to run the statewide advertising customary for a Senate campaign.

• Mike DeWine, incumbent U.S. Senator
• William G. Pierce, engineer
• David Smith, candidate for OH-02 in 2005

Both candidates campaigned as conservative alternatives to DeWine, citing DeWine's support for legal abortion and his role as one of the Republican members of the Gang of 14 who compromised with Democrats in a dispute about judicial appointments.

DeWine won 71.82% of the votes.[3]

• Sherrod Brown (D), U.S. Representative
• Mike DeWine (R), incumbent U.S. Senator
• Richard Duncan (I), 2004 write-in candidate for president.[4]

Because this race was targeted by Democrats, it made it all the more important to the GOP, who desired to retain Senate control. 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".[5]

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."[6][7] DeWine's campaign admitted that the video was actually a still photo of the World Trade Center with smoke digitally added.[6] He also was criticized for using an emotionally charged image to attack his challenger.[7]

Another of DeWine's ads suggested that opponent Sherrod Brown didn't 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.[8] DeWine's ads were changed to state only that he had failed to pay his unemployment taxes until legal action was taken against him.

According to an article in the October 16, 2006, edition of The New York Times, top Republican party officials on the national level determined that DeWine would probably be defeated and were moving financial support from his race to other Republican senatorial candidates they felt were more likely to win.[9]

• 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

During the election cycle, DeWine raised $14.9 million and spent $15.5 million.[10] Brown raised $8.9 million and spent $10.8 million.[11]

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 Rick Santorum in neighboring Pennsylvania 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, came nowhere close to making a dent in Brown's lead. Brown would go on to be reelected to a second term in 2012. In 2018, Brown was re-elected to a third term and DeWine was concurrently elected Governor of Ohio, in a remarkable coincidence.