The 2006 Oklahoma gubernatorial election was held on November 7, 2006. Incumbent Democratic governor Brad Henry won re-election to a second term in a landslide, defeating Republican U.S. representative Ernest Istook. Henry took 66.5% of the vote to Istook's 33.5% and swept all but three counties in the state.
As of 2026, this remains the last time that a Democrat was elected Governor of Oklahoma, or along with the concurrent elections, won any statewide office. Republicans later swept all statewide offices on the 2010 ballot, and have held majorities in both state legislative chambers since the 2008 election.
Background
Though Democrats had dominated state politics for most of Oklahoma's history, the Oklahoma Republican Party had recently gained control of the Oklahoma House of Representatives and held five of the state's six Congressional seats. Henry's opponent, Republican Ernest Istook, was a member of the United States House of Representatives, representing Oklahoma's 5th congressional district.
As in many Southern states, Oklahoma has favored conservative Democrats to the more liberal members of the party. In his first term, Henry had supported some tax cuts and took centrist positions on many political hot button issues.
Democratic primary
Candidates
- Brad Henry, incumbent governor of Oklahoma
- Andrew W. Marr, Jr.
Republican primary
Candidates
- Ernest Istook, U.S. congressman
- Bob Sullivan, former Oklahoma Secretary of Energy
- James A. Williamson, Oklahoma state senator
- Jim Evanoff
Campaign
Istook's strongest opponent in the primary was Bob Sullivan, who positioned himself as the only "non-career politician" in the race. He ran ads featuring Gailard Sartain that attacked his opponents' "career politician" background. The Sartain ads were seen as over the top and may have hurt his chances. Sullivan said education was a top priority and had led an effort to place an initiative petition on the November 2006 ballot that would have required 65 percent of money earmarked for education be spent in the classroom.
General election
The incumbent Democratic governor Brad Henry won the election with more than 66 percent of the vote, beating Republican U.S. representative Ernest Istook.
Results by county
Counties that flipped from Republican to Democratic
- Alfalfa (Largest city: Helena)
- Canadian (Largest city: Yukon)
- Cleveland (Largest city: Norman)
- Comanche (Largest city: Lawton)
- Custer (Largest city: Weatherford)
- Ellis (Largest city: Shattuck)
- Garfield (Largest city: Enid)
- Grant (Largest city: Medford)
- Harper (Largest city: Laverne)
- Jackson (Largest city: Altus)
- Kay (Largest city: Ponca City)
- Kingfisher (Largest city: Kingfisher)
- Logan (Largest city: Guthrie)
- Major (Largest city: Fairview)
- McClain (Largest city: Newcastle)
- Noble (Largest city: Perry)
- Oklahoma (Largest city: Oklahoma City)
- Roger Mills (Largest city: Cheyenne)
- Stephens (Largest city: Duncan)
- Tulsa (Largest city: Tulsa)
- Wagoner (Largest city: Coewta)
- Washington (Largest city: Bartlesville)
- Woodward (Largest city: Woodward)