Vivek Ramaswamy, a Republican former presidential candidate, won his primary race for Ohio governor on Tuesday, setting up a closely-watched contest in November’s election.

The biotech entrepreneur, who was endorsed by Donald Trump and briefly co-led Trump’s so-called “department of government efficiency” (Doge) with Elon Musk at the start of the president’s second term, beat Casey Putsch, the internet personality, to land the nomination.

He was given a late lift by Trump on Tuesday, who called the 40-year-old Ramaswamy on social media “Young, Strong, and Smart!”. He will square off in the 3 November general election with Dr Amy Acton, who won the Democratic nomination unopposed.

Putsch, a political novice who became famous for his series of “car guy” videos on YouTube, had targeted Ramaswamy’s south Asian heritage in campaign ads, but was trounced on Tuesday, winning less than 20% of the vote.

Ramaswamy’s upcoming contest against Acton, who was Ohio’s health director during the Covid-19 pandemic, will be much more competitive, and expensive. No Democrat has won the state since the former governor, Ted Strickland, in 2006, but the party remains hopeful of a flip.

The Cook Political Report in March changed its prediction of the governor’s race to succeed the term-limited Mike DeWine from “likely Republican” to “lean Republican”.

DeWine, meanwhile, endorsed Ramaswamy in the primary, but defended Acton – whom Republicans have nicknamed “Dr Lockdown” – against criticism for her tenure as state health director during the pandemic, insisting that decisions were made by his office.

Acton is running a campaign focused largely on the high cost of living in Ohio, and has previously attacked Ramaswamy’s perceived allegiance to Trump. She has also spoken of her rough childhood, overcoming poverty, homelessness and sexual abuse while growing up in Youngstown.

Her background presents a contrast with Ramaswamy, who was a multimillionaire in his 20s, and whose fortune from his biotech enterprises has reached $2.4bn, according to Forbes.

If elected in November, he has promised to make Ohio an affordable state by rolling back property and income taxes, and making technology advances and energy reforms to reduce consumers’ bills.

Ramaswamy is also a proponent of so-called parental rights in education. “A world-class education is the birthright of every Ohioan & we’ll make sure that’s what they get, from the inner cities to Appalachia,” he wrote in a post on X on Tuesday night, shortly after his primary victory was confirmed.

Ramaswamy’s run for the 2024 Republican presidential nomination started brightly, but he suspended his campaign in January that year after a disappointing fourth-place finish in the Iowa caucuses.

He was appointed as a co-leader of the Doge cost-cutting initiative after Trump won the November 2024 election, but left the position days after the president’s return to the White House in January 2025 amid reports of a falling out with Musk, the world’s richest man.

In another consequential Ohio primary race on Tuesday, Sherrod Brown, the former US senator, easily beat his Democratic rival, Ron Kincaid, and will face off against the Republican incumbent, Jon Husted, in a special election in November.

The winner will serve the remainder of the term won by JD Vance in 2022. Brown, first elected to the chamber in 2006, lost his seat in the 2024 election to Bernie Moreno, a Republican.