Hunter is the only surviving son of Biden, who lost his first wife Neilia and their 15-month-old daughter, Naomi, in a car crash in 1972. Four decades later, his eldest son Beau, who survived the crash with Hunter and was often touted as a potential future president, died of brain cancer.

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The trial could embarrass the Bidens by calling two of Hunter’s former partners and going through his now-famous laptop to air incriminating information.

One is his former wife, Kathleen Buhle, who is locked in a long legal battle with him over unpaid alimony; the other is Hallie Biden, the widow of Beau. She later dated Hunter for a period and is expected to testify about drugs and paraphernalia she found in his possession several times.

The timing of the trial makes it trickier for Democrats to capitalise on Trump’s conviction, after a jury in New York found him guilty of 34 counts of falsifying business records over a hush money scheme designed to sway the 2016 election.

Judge Juan Merchan has set Trump’s sentencing hearing for July 11, about two weeks after the first presidential debate and four days before the Republican National Committee.

While falsifying business records come with a maximum four years’ jail for each count (although New York caps this particular offence at a maximum of 20 years) the non-violent nature of Trump’s crimes and his lack of prior convictions means a probation, fine or some other lesser sentence is more likely.

Merchan also telegraphed his reluctance to put a former president and leading Republican candidate in jail during the trial, while scolding Trump for continuously violating a gag order designed to stop him from attacking witnesses.

“Mr Trump, it’s important you understand, the last thing I want to do is put you in jail. You are the former president of the United States and possibly the next president as well,” Merchan told him.

“The magnitude of this decision is not lost on me, but at the end of the day I have a job to do. So as much as I don’t want to impose a jail sanction … I want you to understand that I will if necessary and appropriate.”

Trump has nonetheless used his conviction to fundraise an estimated $US70 million ($105 million) since the verdict was announced, according to his daughter-in-law, Lara Trump, who is now the co-chair of the Republican National Convention.

And in an interview with Fox & Friends over the weekend, Trump warned that jailing him would “be tough for the public to take” adding that: “At a certain point, there’s a breaking point.”

The Biden-Harris campaign seized on the comments, saying that “yet again, diminished man, white-collar crook, and convicted felon Donald Trump suggested his supporters engage in violence”.

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“This unhinged man cannot be our president,” said Democrats spokesman James Singer.

Hunter Biden’s trial comes after Republicans spent months investigating a so-far unproven claim that the president profited from his son’s foreign business deals, which included lucrative contracts in Ukraine and China.

They have also claimed there is a “two-tiered” legal system in the US – although it was the president’s Justice Department that appointed the special counsel who brought the charges against Hunter.

If convicted, the recovering addict could face a jail term of up to 25 years and $US750,000 in fines. However, as a non-violent offender, he is more likely to get a lesser sentence if found guilty.