MILWAUKEE: Former President Donald Trump chose Sen. JD Vance of Ohio as his running mate on Monday, picking a one-time critic who became a loyal ally and is now the first millennial to join a major-party ticket at a time of deep concern about the advanced age of America’s political leaders.

“After lengthy deliberation and thought, and considering the tremendous talents of many others, I have decided that the person best suited to assume the position of Vice President of the United States is Senator J.D. Vance of the Great State of Ohio,” Trump said in a post on his Truth Social network as the Republican National Convention got underway in Milwaukee.

Hours later, Vance formally received his party’s formal nomination after walking onto the floor of the convention to Merle Haggard’s “American First”.

He and Trump — who had a large bandage on his right ear after Saturday’s shooting — sat next to each other in Trump’s box during the convention’s opening night program.

The 39-year-old Vance rose to national fame with the 2016 publication of his memoir, “Hillbilly Elegy”. He was elected to the Senate in 2022 and has become one of the staunchest champions of the former president’s “Make America Great Again” agenda, particularly on trade, foreign policy and immigration.

But he is largely untested in national politics and is joining the Trump ticket at an extraordinary moment in American history.

An attempted assassination of Trump at a rally Saturday has shaken the campaign, bringing new attention to the nation’s coarse political rhetoric and reinforcing the importance of those who are one heartbeat away from the presidency.

Vance himself faced criticism in the wake of the shooting for a post on X that suggested President Joe Biden was to blame for the violence.

“The central premise of the Biden campaign is that President Donald Trump is an authoritarian fascist who must be stopped at all costs,” Vance wrote.

“That rhetoric led directly to President Trump’s attempted assassination.”

Law enforcement has not yet specified a motivation for the shooting.

Why Vance was chosen over the other finalists

The pick is sure to energise Trump’s loyal base.

Vance has become a fixture on the conservative media circuit and frequently spars with reporters on Capitol Hill, helping establish him as the kind of leader who could carry Trump’s mantle into the future, beginning with the next presidential election in 2028.

But the pick also means that two white men will now lead the Republican ticket at a time when Trump has sought to make inroads with Black and Latino voters.

In his post announcing his pick, Trump said Vance “will be strongly focused on the people he fought so brilliantly for, the American Workers and Farmers in Pennsylvania, Michigan, Wisconsin, Ohio, Minnesota, and far beyond.”

Several of those Midwestern states are expected to play a critical role in November’s election.

But Vance also had another advantage: his chemistry with Trump. Personal relationships are extremely important to the former president and he and Vance have developed a strong rapport, speaking on the phone regularly.

Trump has also complimented Vance’s looks, saying he reminded him of “a young Abraham Lincoln”.

Trump formally offered Vance the job in a phone call that came about 20 minutes before his Truth Social post, according to a person familiar with the call who requested anonymity to share details of the private conversation.

Vance told Fox News host Sean Hannity in his first interview since his selection that he knew Trump was calling with big news, but didn’t know if it was good or bad.

He said the former president told him he could help win Midwestern swing states such as Michigan, and thought he would do well in the vice presidential debate.

Trump had long said he wanted to dramatically reveal his pick onstage at the convention, which he said would make it more “interesting” and “exciting”.

The timing is later than in recent cycles, but hardly unprecedented.

In 1980, Ronald Reagan made his decision less than 24 hours before he formally accepted the GOP nomination, and George H.W. Bush waited until his convention in 1988.

Biden’s re-election campaign issued a statement calling out Vance for saying, had he been vice president, he would have allowed “multiple slates of electors” to challenge Biden’s victory over Trump four years ago.

Trump repeatedly promoted falsehoods about election fraud before and after Jan. 6, 2021, when rioters loyal to the former president stormed the Capitol to try to stop the certification of his loss.

“Donald Trump picked J.D. Vance as his running mate because Vance will do what Mike Pence wouldn’t on January 6: bend over backwards to enable Trump and his extreme MAGA agenda, even if it means breaking the law and no matter the harm to the American people,” Biden campaign chair Jen O’Malley Dillon said in the statement.

Trump had spent months testing the field, assessing how his contenders performed on television, at fundraisers and on rally stages.

Several joined him at his criminal hush money trial in New York. Others were there at the debate last month, where Biden’s disastrous performance upended his campaign, leading to widespread calls for him to step aside in favour or a younger candidate.

Vance once was a harsh Trump critic

The relationship between Vance and Trump has been symbiotic.

Vance’s fame grew in tandem with Trump’s unlikely rise from a reality television star to Republican presidential nominee and eventually president.

During the early stages of Trump’s political career, Vance cast him as “a total fraud”, “a moral disaster” and “America’s Hitler”.

But like many Republicans who sought relevance in the Trump era, Vance eventually shifted his tone. He said he was proved wrong by Trump’s performance in office and evolved into one of his most steadfast defenders.

“I was certainly sceptical of Donald Trump in 2016, but President Trump was a great president and he changed my mind,” Vance said in his interview with Hannity.

“I think he changed the minds of a lot of Americans, because again he delivered that peace and prosperity.”

Vance was rewarded for his turnaround during his bid for an open Senate seat in 2022, during which he landed Trump’s coveted endorsement and rode it to victory in a crowded Republican primary and a general election hard fought by Democrats. He is close to Trump’s son Donald Jr.

“Listen, I’ve seen him on TV,” Donald Trump Jr. said of Vance, speaking to CNN from the convention floor.

“I’ve seen him prosecute the case against the Democrats. No one’s more articulate than that. And I think his story, his background, really helps us in a lot of the places that you’re going to need from the Electoral College standpoint.”

Vance is now a Trump loyalist who has challenged the legitimacy of criminal prosecutions and civil verdicts against him and questions the results of the 2020 election.

He told ABC News in February that if he had been vice president on Jan. 6, 2021, he would have told states where Trump disputed Biden wins “that we needed to have multiple slates of electors, and I think the U.S. Congress should have fought over it from there.”

“That is the legitimate way to deal with an election that a lot of folks, including me, think had a lot of problems in 2020,” he said.

Many states adopted emergency measures four years ago to allow people to vote safely during the COVID-19 pandemic. But judges, election officials in both parties and Trump’s own attorney general have concluded there was no evidence of widespread voter fraud in the 2020 election.

Vance’s book vaulted him to national prominence

Vance’s book — subtitled “A Memoir of a Family and Culture in Crisis” — detailed life in Appalachian communities that drifted from a Democratic Party many residents found disconnected from their daily travails.

It was embraced for its insights into Trump’s appeal in middle America, where manufacturing job losses and the opioid crisis had driven many families like his into poverty, abuse and addiction, but it was also criticised for sometimes oversimplifying rural life and ignoring the role of racism in modern politics.

The tale of Vance’s hardscrabble childhood in Middletown, Ohio, where he was born, and his familial eastern Kentucky hills region also captivated Hollywood.

Ron Howard made it into a 2020 movie starring Amy Adams as Vance’s mother and Glenn Close as his beloved “Mamaw”.

Because of that difficult upbringing, “I actually understand a little bit what people are going through,” Vance said on Fox.

“Yeah, it was tough when I was dealing with it, but now I really do think it’s a blessing that’s given me a perspective a lot of politicians don’t have.”

With his grandmother’s encouragement, Vance went on to serve in the Marine Corps, including in Iraq, and to graduate from Ohio State University and Yale Law School. From there, he joined a Silicon Valley investment firm before returning to Ohio to launch a non-profit that he said would aim to develop opioid addiction treatments that might be “scaled nationally”.

Ultimately, Our Ohio Renewal failed at that mission and was shuttered. During the 2022 campaign, then-U.S. Rep. Tim Ryan, his Democratic rival, charged that the charity was little more than a front for Vance’s political ambitions.

Ryan pointed to reports that the organisation made payments to a Vance political adviser and conducted public opinion polling, even as its actual efforts to address addiction largely floundered. Vance denied the characterisation.

As a senator, Vance has shown some willingness to work across the aisle. He and Ohio’s senior senator, Democrat Sherrod Brown, have teamed up on a number of issues important to the state, including fighting for funding for a $20 billion chip facility Intel is building in central Ohio and introducing rail safety legislation in response to the fiery derailment in East Palestine, Ohio.