When he was picked as Donald Trump's running mate in July, JD Vance's rise through the Republican ranks was confirmed.

Within the space of eight years, he'd gone from bestselling author and a staunch critic of the former president to a darling of the "Make America Great Again" movement and the face of its new guard.

Many pundits see him as heir apparent to MAGA and he will be among the favorites to be the Republican presidential candidate in 2028 — irrespective of this year's outcome.

While Donald Trump's brash brand of politicking is a natural extension of the larger-than-life persona he carved out over four decades in the public eye, Vance, a 40-year-old father of three, is from another side of America, and his rise to the vice presidency has been unconventional by Republican standards.

Vance was born James Donald Bowman and raised mostly by his maternal grandparents — whose surname he later adopted — in a steel manufacturing town in Ohio while his mother struggled with drug and alcohol use.

After graduating from high school, Vance joined the US Marines and spent six months in Iraq in a noncombat role as a military journalist in 2005.

On returning to the United States, he would graduate from both Ohio State University and Yale Law School, before making the switch from law to tech investing in California, where he started his own venture capital firm.

'Never Trumper' to MAGA senator

It was in May 2016 that Vance entered the public eye with the publication of his acclaimed "Hillbilly Elegy: A Memoir of a Family and Culture in Crisis."

The bestseller reflected on Vance's upbringing and was considered a window into the lives of people in the declining manufacturing region known as the Rust Belt just months before slim margin wins in the states of Wisconsin, Michigan and Pennsylvania swept Trump to power in 2016.

In an interview with NPR's "Fresh Air" program at the time, Vance notably said he couldn't "stomach Trump" and would consider voting for Hillary Clinton, but also, somewhat prophetically, suggested that the Trump phenomenon was buoyed by the support of white working-class voters who "aren't necessarily economically destitute but in some ways feel very culturally isolated and very pessimistic about the future. That's one of the biggest predictors about whether someone will support Donald Trump. It may be the biggest predictor."

Among those heaping praise on the book was PayPal co-founder Peter Thiel.

The New York Times reported in July that Thiel  — a long-standing mentor of Vance's and one of the first high-profile Silicon Valley figures to support Trump in 2016 — brokered an initial meeting between the former president and his future VP in 2021.

Vance would recant his position as "a Never Trump guy" when he successfully ran in the 2022 Republican primary to represent Ohio in the US Senate.

Campaign controversies and polished performances

Vance has courted controversy on the campaign trail but has also pulled his weight for the Trump ticket as a key campaign messenger.

Shortly after his selection as running mate, a 2021 interview resurfaced in which Vance described the United States as a country run by "childless cat ladies" — a comment rebuked by Democrats, as well as Taylor Swift and other celebrities.

Vance later raised the ire of communities in his home state of Ohio after he shared false claims made on social media that Haitian immigrants were eating dogs in Springfield. Those claims were amplified by Trump in his debate against Kamala Harris.

His debate performance against Tim Walz saw him come away with a narrow win in the eyes of critics. His measured effort was summarized by the press as "polished" (Politico), "crisp" and "dominant" (New York Times) and "slick" (CNN).

But the elephant in the room was his inability to concede that Trump had lost the 2020 election to Joe Biden, something his opponent made sure to seize on.

Given suggestions he may the heir-apparent to a post-Trump Republican party, Vance's words and actions may be some of the most closely scrutinized of any vice presidential candidate in recent times.

Edited by: Milan Gagnon and Rob Mudge