Donald Trump picks Ohio senator JD Vance as his running mate for ...

Donald Trump has selected Ohio senator JD Vance as his 2024 running mate, at the beginning of the Republican National Convention. 

He's seen as a staunch conservative that could boost voter turnout among Mr Trump's base.

Mr Trump will formally accept the party's nomination as its presidential candidate in a prime-time address later today.

Donald Trump has been officially nominated as the Republican presidential candidate for the 2024 election, and selected Ohio senator JD Vance as his running mate. 

The news comes at the beginning of the four-day Republican National Convention in Milwaukee to nominate the party's presidential ticket.

In an announcement on his social media platform Truth Social, Mr Trump said he had given the decision "lengthy deliberation and thought, considering the tremendous talents of many others". 

"As vice-president, JD will continue to fight for our constitution, stand with our troops, and will do everything he can to help me MAKE AMERICA GREAT AGAIN," he wrote.

It comes just two days after Mr Trump survived an assassination attempt in Pennsylvania, and hours after he secured a major legal victory when a federal judge dismissed the classified documents case against him.

Mr Trump is due to formally accept the party's nomination in a prime-time address later today. He has foreshadowed a speech that focuses more on national unity than highlighting differences with President Joe Biden.

"This is a chance to bring the whole country, even the whole world, together. The speech will be a lot different, a lot different than it would've been two days ago," Mr Trump told the Washington Examiner.

A staunch conservative from a Republican state, James David Vance rose to prominence as the author of the bestselling memoir Hillbilly Elegy, and is seen as a candidate that could increase the odds of voters turning out at the election in November. 

While election watchers view him as unlikely to bring new voters around to supporting the Trump ticket, he is popular with the former president's base. Some of Mr Trump's supporters had been pushing him to select a woman or person of colour as his running mate in a bid to expand support beyond white male voters. 

In the past Mr Vance has been a vocal critic of the former president, describing him in 2016 as "an idiot", a "cynical asshole" and "America's Hitler". However, in the years since he has become one of Mr Trump's strongest supporters. 

During Mr Trump's time in office, Mr Vance said he came to support his policies — and in 2022 he secured the former president's endorsement when he ran for a seat in the US Senate. 

"I wasn’t always nice, but the simple fact is, he's the best president of my lifetime, and he revealed the corruption in this country like nobody else," he said at a rally ahead of the 2022 midterms. 

Since being elected to the Senate, Mr Vance has been a strong defender of the Make America Great Again agenda, particularly on trade, foreign policy and immigration, and has openly challenged the legitimacy of criminal prosecutions against Mr Trump. 

He remains a proponent of Mr Trump's claims that the 2020 election was "stolen", and as recently as February this year he told news outlets that if he had been vice-president on January 6, he would have told states where Mr Trump disputed the results "that we needed to have multiple slates of electors, and I think the US Congress should have fought over it from there". 

Donald Trump has chosen one of his most staunch defenders as his running mate. (Reuters: Gaelen Morse)

In the wake of this week's shooting in Pennsylvania, Mr Vance suggested 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," he wrote on X. 

"That rhetoric led directly to President Trump's attempted assassination."

The suggestion was roundly criticised by Democrats. Police have not yet specified a motivation for the shooting. 

In a statement, Mr Biden said his opponent's choice of running mate would serve billionaires and corporations and harm the American people. 

"Donald Trump picked JD Vance as his running mate because Vance will do what Mike Pence wouldn't do 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," he wrote.

ABC/wires