Democrat Cindy Holscher has won the Kansas governor's race, defeating Republican Ty Masterson in the closest contest for the office in more than half a century, the Associated Press declared on Thursday.

The AP called the race at 5:43 p.m. EST on Thursday, more than a week after the November 3 midterm elections, after days of counting provisional ballots and a state-required audit of the narrow result. Holscher led by 7,358 votes, taking 50.3 percent of the vote.

Holscher, a state senator from Overland Park since 2021, will succeed term-limited Governor Laura Kelly, a fellow Democrat who served eight years. The victory breaks a 60-year streak in Kansas of electing governors from the party opposite that of their immediate predecessor, and it is the first time in state history that voters have elected back-to-back Democratic governors.

It was the closest Kansas governor's race since 1974, when Republican Robert Bennett beat Democrat Vern Miller by 3,677 votes. Holscher's running mate, Wichita Democrat KC Ohaebosim, will become lieutenant governor.

Masterson, the president of the GOP-controlled state Senate, ran with the backing of President Donald Trump and was heavily favoured by outside spending, with Republicans outspending Democrats on advertising by nearly three to one. Masterson conceded on Thursday, saying in a social media post that he had called Holscher to congratulate her.

Holscher campaigned on affordability, promising a temporary moratorium on building new data centers, expanding Medicaid and legalising marijuana. She captured more than 60 percent of the vote in Johnson County, her home base, offsetting Masterson's large margins in solidly Republican rural areas.

The result extends a wave of Democratic victories across the country. Democrats had already secured a majority of governorships nationwide for the first time in two decades, and Kansas was seen as the race most likely to flip from Democratic to Republican control among the 36 governor contests on the ballot. Democrats also won four statewide contests in Kansas for the first time since 1958.

Holscher takes office on January 11, 2027.