Dr. Amy Acton secured a stunning victory in the race for Ohio governor on Tuesday, overcoming more than $100 million spent against her to become the first Democrat to win the post in 20 years and the first woman elected to the state's highest office.

The public health physician and former COVID-19-era state health director defeated Trump-backed Republican Vivek Ramaswamy, a biotech billionaire and 2024 presidential candidate. She ran on affordability and expanding healthcare access, appealing to working- and middle-class voters by highlighting her background as an Ohio native who experienced childhood homelessness and lived in a tent for one winter.

The contest was roiled during its final month when Ramaswamy aired an attack advertisement featuring Acton’s estranged mother, who claimed Acton lied about her upbringing and urged residents not to vote for her.…