2018Final resultsSpecial election
2018 special election for Ohio's 12th District
U.S. House · Ohio
Troy Balderson (R) won with 50.1% of the vote, defeating Danny O'Connor (D) by 0.8 points.
Troy BaldersonRepublican · winner
50.1%104,328
Danny O'ConnorDemocrat
49.3%102,648
Joe ManchikGreen
0.6%1,165
208,141 votes
Source: Federal Election CommissionUpdated Oct 3, 2026, 3:20 AM ET
The seat over time
D − R margin in this seat's races around 2018
Races before and after
Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)
Polls against the result
- Poll with O'Connor ahead
- Poll with Balderson ahead
- Result
| Pollster | Dates | Sample | O'Connor | Balderson | Margin | Adjusted | Miss vs result | Grade | Release |
|---|---|---|---|---|---|---|---|---|---|
| Emerson College | Aug 3 | 431 | 47 | 46 | D+1 | — | +1.8 | A+ | Wikipedia |
| Monmouth University Polling Institute | Jul 28 | 423 | 46 | 45 | D+1 | — | +1.8 | A− | Wikipedia |
| Public Policy PollingD-sponsored | Jul 28 | 617 | 44 | 48 | R+4 | — | −3.2 | B+ | Wikipedia |
| GBAOD-sponsored | Jul 24 | 500 | 45 | 48 | R+3 | — | −2.2 | C | Wikipedia |
| GBAOD-sponsored | Jul 12 | 600 | 43 | 48 | R+5 | — | −4.2 | C | Wikipedia |
| JMC Analytics | Jun 15 | 500 | 35 | 46 | R+11 | — | −10.2 | C | Wikipedia |
| GBAOD-sponsored | Jun 11 | 500 | 41 | 48 | R+7 | — | −6.2 | C | Wikipedia |
| Monmouth University Polling Institute | Jun 9 | 263 | 35 | 50 | R+15 | — | −14.2 | A− | Wikipedia |
Adjusted: after correcting for the pollster's house effect and likely-voter screens. Miss: the poll's margin minus the result; + means the poll leaned Democratic. Grade: the pollster's accuracy in past elections, A+ to D (pollster ratings).
Source: Each poll's release, via FiveThirtyEight poll listsUpdated Aug 3, 2018