Who is Trump’s pick for vice president? JD Vance?

“I never supported Trump. I never liked him.”

“Oh my god, you’re such an idiot.”

“I think he’s reprehensible.”

That’s what JD Vance said in interviews and on Twitter in 2016, when his memoir, Hillbilly Elegy, was published, catapulting him to fame.

In just a few years, Mr. Vance has become one of Mr. Trump’s staunchest allies.

A few years later, the first-term senator from Ohio is now Trump’s vice presidential running mate — and, as an early frontrunner for the 2028 Republican presidential nomination — with a proven conservative voting record and Midwestern roots that will surely help boost vote counts.

Indeed, Mr. Vance has made a habit of pivoting. How did he rise from a tough upbringing to the highest echelons of American politics?

Mr. Vance was born James David Bowman in Middleton, Ohio, the son of a drug addict mother and a father who left the family when Mr. Vance was a child.

He was raised by his grandparents, “Grandpa and Grandma,” whom he described sympathetically in his 2016 memoir, “Hillbilly Elegy.”

Although Middleton is located in Ohio’s Rust Belt region, Mr. Vance has strong ties to his family roots, which are located slightly south in Appalachia, a vast inland mountainous region that stretches from the Deep South to the edge of the industrial Midwest. The region includes some of the poorest areas of the country.

Mr. Vance paints an honest picture of the trials, pain and bad decisions his family and friends endured. His book also takes a distinctly conservative view — depicting them as chronic spendthrifts, welfare dependents and mostly unable to fend for themselves.

He wrote that he saw Appalachians “responding to adverse circumstances in the worst possible way” and that they were the product of “a culture that encouraged social decay rather than resisted it.”

“The truth is hard,” he wrote, “and the hardest truth for mountain people is that they must tell their own truth.”

Despite his disdain for “elites” and exclusive society, he portrays himself as the counterpart to the chronic failures of those he grew up with.

By the time the book was published, Mr. Vance had worked his way away from Middleton: He joined the Marines and served in Iraq, then went to Ohio State University, Yale Law School and found a job as a venture capitalist in California.

Hillbilly Elegy not only made him a bestselling author but also a sought-after commentator, often called upon to explain Donald Trump’s appeal to white working-class voters and who rarely missed an opportunity to criticize the Republican candidate of the day.

“I think this election did have a negative impact, particularly on the white working class,” he said in an October 2016 interview.

“It does so by giving people an excuse to blame someone else, Mexican immigrants, Chinese trade, Democratic elites or whatever.”

In 2017, Mr. Vance returned to Ohio to continue his venture capital career. He and his wife, Usha Chilukuli Vance, whom he met at Yale, have three children.

His name had long been buzzing as a political candidate, and when Ohio Republican Sen. Rob Portman decided not to run for re-election in 2022, he saw his opportunity.

Although his campaign got off to a slow start, he received a $10m (£7.7m) donation from his former boss, Silicon Valley powerbroker Peter Thiel, to help him get started. But the real obstacle to his election in the increasingly Republican state of Ohio is his past criticism of Trump.

He apologized for his previous remarks, successfully repaired the relationship and won Trump’s support, making him a leader in the Republican camp and eventually entering the Senate.

In the process, Mr. Vance has become an increasingly prominent player in the “Make America Great Again” political arena and has all but fully subscribed to Mr. Trump’s agenda.

In the Senate, he was a trusted conservative who supported populist economic policies and became one of Congress’ biggest skeptics of aid to Ukraine.

Because of his short tenure in the Democratic-led House, few of his bills have advanced, and those that have tended to be messaging rather than policy changes.

In recent months, Mr. Vance has introduced bills to suspend federal funding to colleges that host refugee camps or Gaza-Israel war protests, as well as to colleges that employ undocumented immigrants.

Mr. Vance has demonstrated his hawkish stance on foreign policy as well as his background in finance by sponsoring a bill in March that would cut off the Chinese government from American capital markets if it failed to comply with international trade laws.

Mr. Vance, who was baptized a Catholic in 2019, opposes abortion but has recently supported Mr. Trump’s view that the matter should be left to the states to decide.