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 County results Congressional district resultsKoster: 40–50% 50–60% 60–70% 80–90% Martin: 40–50% 50–60% 60–70% | |||||||||||||||||
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The2012 Missouri Attorney General election was held on November 6, 2012, alongside thepresidential andgubernatorial elections. The incumbentMissouri Attorney GeneralChris Koster, aDemocrat, won re-election for a second full term against Republican attorneyEd Martin. As of 2026, this is the last time a Democrat was electedAttorney General of Missouri.
Koster was originally elected as attorney general in 2008 as aDemocrat after switching from theRepublican Party. Koster won despite accusations that his campaign violated state law in raising money from multiple committees. He also survived the disclosure that he played a supporting role in a plagiarism episode that damaged Attorney GeneralWilliam L. Webster’s campaign for governor in 1992. Fresh out of law school, Koster worked for Webster, a Republican, as an assistant state attorney general.[1]
He defeated State Representative Margaret Donnelly in the Democratic primary for the nomination for Missouri Attorney General and won against Republican state senatorMichael R. Gibbons in the general election, 53%-47%.[2] He was sworn in as attorney general on January 12, 2009, succeedingJay Nixon, who had served since 1993.
| Poll source | Date(s) administered | Sample size | Margin of error | Ed Martin | Adam Warren | Undecided |
|---|---|---|---|---|---|---|
| Public Policy Polling[7] | August 4–5, 2012 | 590 | ± 4.0% | 46% | 17% | 37% |
100% reporting (3,420 of 3,420 precincts)[8]
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Ed Martin | 373,434 | 71.6 | |
| Republican | Adam Lee Warren | 148,432 | 28.4 | |
| Total votes | 521,866 | 100.0 | ||
Martin, who served as chief of staff for GovernorMatt Blunt from 2006 until November 2007, won theRepublican primary in a landslide, 72%-28% and became the party's nominee.
Koster was unopposed for theDemocratic nomination.
| Poll source | Date(s) administered | Sample size | Margin of error | Chris Koster (D) | Ed Martin (R) | Other | Undecided |
|---|---|---|---|---|---|---|---|
| Mason-Dixon[9] | October 23–25, 2012 | 625 | ± 4% | 51% | 37% | — | 12% |
| Public Policy Polling[10] | October 19–21, 2012 | 582 | ± 4.1% | 48% | 38% | — | 13% |
| Public Policy Polling[11] | August 20, 2012 | 500 | ± 4.4% | 41% | 39% | — | 20% |
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Democratic | Chris Koster (incumbent) | 1,482,381 | 55.81% | +2.98 | |
| Republican | Ed Martin | 1,081,510 | 40.71% | −6.46 | |
| Libertarian | Dave Browning | 92,465 | 3.48% | N/A | |
| Total votes | 2,668,064 | 100.00% | N/A | ||
| Democratichold | |||||
On election day, Koster defeated Martin by a wide margin of over 14 percentage points, an increase from his 5% margin of victory in 2008. This was despiteRepublicanMitt Romney defeatingDemocratic PresidentBarack Obama in the concurrentpresidential election in Missouri, although other incumbent state Democratic officials were re-elected as well. Governor Jay Nixon wonre-election by more than 12 percentage points, SenatorClaire McCaskill wonre-election by over 15 percentage points, andClint Zweifel won by 5 percentage points.Jason Kander was alsoelected Secretary of State by just over one percentage point.
Koster won six of eight congressional districts, including four that elected Republicans.[12]
| District | Koster | Martin | Representative |
|---|---|---|---|
| 1st | 83% | 15% | Lacy Clay |
| 2nd | 51% | 46% | Todd Akin (112th Congress) |
| Ann Wagner (113th Congress) | |||
| 3rd | 50% | 46% | Russ Carnahan (112th Congress) |
| Blaine Luetkemeyer (113th Congress) | |||
| 4th | 52% | 44% | Vicky Hartzler |
| 5th | 67% | 29% | Emanuel Cleaver |
| 6th | 51% | 45% | Sam Graves |
| 7th | 44% | 52% | Billy Long |
| 8th | 48.0% | 48.3% | Jo Ann Emerson |
Official campaign websites
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