Ohio Sen. J.D. Vance has come a long way since his memoir "Hillbilly Elegy" launched him into the national spotlight eight years ago.

And now Vance could reach new heights in his transformative career, possibly serving as vice president to the man he once heavily criticized, former President Donald Trump.

Vance's rise began when he released his memoir "Hillbilly Elegy," where he reflects on his upbringing and growing up in a low-income family involved in violence and addiction in Middletown, Ohio -- part of America's Rust Belt.

Vance overcame his childhood struggles and attended Ohio State University and Yale Law School, he recounted in his book. After working at a corporate law firm, he moved to San Francisco to work as a venture capitalist in the tech industry before moving back to Ohio.

A 'never-Trump guy'

Vance's memoir led him to become an emissary between the media, the political class and those who live in the Rust Belt -- a group that helped send Trump to the White House in 2016.

During this time, Vance would make clear his disdain for Trump, saying he was a "never-Trump guy" in an interview with Charlie Rose in 2016.

In August 2016, he told ABC News that he didn't see Trump "offering many solutions."

But Vance would eventually align with the former president, praising his time in office and apologizing for his attacks on him during an interview with Fox News in July 2021. His apology came around the same time Vance entered the race for the open Ohio Senate seat, which became the most competitive GOP primary of the 2022 election cycle.

But one of Vance's close friends -- who spoke to ABC News on the condition of anonymity -- said many media organizations' negative response to Trump contributed to Vance's shift in perception.

​​"It was a gradual shift that I think was really triggered by the media and the left's overreaction to Trump," the friend said.

Fox News anchor Bret Baier confronted Vance last month about his previous anti-Trump comments.

"Look, I was wrong about Donald Trump. I didn't think he was going to be a good president, Bret," Vance said. "He was a great president, and it's one of the reasons why I'm working so hard to make sure he gets a second term."

The two would go on to mend their relationship, with the former president endorsing Vance in the very crowded Ohio GOP Senate primary in May 2022. The endorsement helped Vance win the primary and general elections in November.

Vance's shift to politics

Prior to embracing Trump and taking on a life in politics, Vance already had a successful life, finding success through his book and work. But by coming out and aligning himself with Trump, Vance left his old lifestyle behind.

"He had the life that most people run for office to get one day -- the elites loved and respected him. But by running for Senate and coming out as pro-Trump, he was knowingly and happily turning his back on those very people. Not many people would make the decision to reject the charmed life that came with being the toast of the elites the way J.D. did," the same close friend told ABC News.

Vance's start in Congress as the junior senator from Ohio began shortly before the East Palestine, Ohio, toxic train derailment, which became the first major disaster Vance responded to as an elected official.

The accident led MAGA-aligned Vance to work with Democratic Sen. Sherrod Brown, Ohio's senior senator, on Congress' railway safety legislation.

However, Vance has stayed true to his tough conservative brand, including opposing aid to Ukraine.

But as Vance's political stock began to rise, so did his ability to become an effective communicator for Trump's reelection campaign.

During Trump's reelection campaign, Vance has been an active surrogate, attending campaign events, doing media hits and helping court wealthy donors for the campaign. Most recently, Vance attended fundraisers for Trump in Ohio and California. Vance also helped organize the June Silicon Valley fundraiser hosted by entrepreneur David Sacks and acted as the point of contact between Sacks and the Trump campaign. The fundraiser raised $12 million.

That same day as his fundraiser for Trump, Sacks announced he would be backing him in the election on X.

"With respect to economic policy, foreign policy, border policy, and legal fairness, Trump performed better. He is the President who deserves a second term," Sacks wrote on X.

Sacks told Axios that Vance was "instrumental in making the Trump event happen."

Overall, Vance has been strong at fundraising for Trump, given his ties to Silicon Valley through previous work as a former venture capitalist.

What Vance could bring to the ticket

With Trump expected to announce his running mate in the coming days -- and Vance being one of the top contenders, allies of both Vance and Trump say Vance's ability to be an effective messenger for the campaign sets him apart from others.

"J.D. was always talented at delivering an effective message on TV and on the campaign trail, but over time, he just got better and better," said a close friend of Vance. "He's one of the few people I've seen in politics, who really has an ability to appeal to both working-class voters because of his blue-collar background, and also highly educated suburban voters because of his intelligence."

Vance, who is currently 39 years old and will turn 40 later this summer, could become one of the youngest vice presidents in U.S. history if selected as Trump's running mate and they win in November.

But compared to others in the mix who are also under consideration for being Trump's running mate, such as Sen. Marco Rubio and North Dakota Gov. Doug Burgum, Vance has the least political experience.

However, many of those who spoke to ABC News for this article pointed to Vance's work ethic and intelligence as indicators of his performance as vice president.

The continued fallout from President Joe Biden's debate with Trump has left him more optimistic about his chances of winning this November, allowing him to be more flexible in picking a running mate, senior GOP sources told Axios.

An Ohio GOP operative told ABC News that Vance's background is critical to his effectiveness as a messenger for the Trump campaign. The operative emphasized Vance's background growing up in the Rust Belt and how it would be crucial in attracting those voters who have felt left behind by both parties.

"That experience that he had growing up in Appalachian watching the collapse of the Rust Belt… [his] book, it spoke to what was happening in American politics at that moment in time, in a way that nobody else really had captured, and he has lived that out …"

A source close to Trump told ABC News that Vance "is going to be successful because he actually believed the things that he was saying."

"He's gonna be believable because he's sincere," the source said.

The former president's eldest son, Donald Trump Jr. -- who also developed a friendship with Vance -- has publicly advocated for Vance to be his father's running mate because of his policies. Donald Trump Jr. also said on his podcast that he would like to see Vance debate Vice President Kamala Harris.

It seems Democrats are also aware of the possible threat Vance could pose to Biden's reelection campaigns -- particularly in a match-up against Harris at the debate set for later this summer.

In June, Harris' former communication director Ashley Etienne said on CNN that she believes Vance "would pose the greatest threat" to Harris in a vice-presidential debate.

"He's an incredible debater," Etienne said. "I think he has this quality that makes him seem palpable to the 1 to 2% that are undecided, that will actually pay attention to the debates … I think he's just got a quality about him where he's super smart, and sharp and quick-witted. I think it's going to be a challenge to see the two of them face to face."