US President Joe Biden has issued a presidential pardon for his son Hunter, who was facing sentencing for two criminal cases.

The move has proven controversial, since the outgoing president previously ruled out such a move. But he claimed the cases against his son were politically motivated.

His use of his pardoning powers continues a tradition of presidents on both sides of the American political divide granting clemency to people close to them.

Hunter Biden was awaiting sentencing later this month in two federal cases.

In June, he became the first child of a sitting US president to be criminally convicted – in a case relating to his gun ownership. He was found guilty by a jury in Delaware of three charges for lying about his drug use on a form when buying a handgun.

He was also awaiting sentencing after pleading guilty in September in a federal tax case that centred on whether he paid enough tax from 2016-19. The nine charges included failure to file and pay his taxes, tax evasion and filing a false return.

He faced up to 25 years in prison in the gun case and 17 years in the tax case, though he was likely to get much shorter tariffs and to serve the two sentences concurrently, experts told the New York Times.

The US Constitution decrees that a president has the broad “power to grant reprieves and pardons for offences against the United States, except in cases of impeachment”.

In this case, the president’s “full and unconditional pardon” is unusually sweeping.

It covers any potential federal crimes the younger Biden may have committed during a period of more than 10 years from January 2014 to December 2024.

That spans a period beyond Hunter Biden’s tax and gun offences and dates back to the year he joined the board of Burisma, a Ukrainian energy company, while his father, then US vice-president, had a key role in US policy towards Kyiv.

The wording of the pardon also makes clear that it covers any offence that the younger Biden “has committed or may have committed”.

The pardon represents legal forgiveness, ends any further punishment and restores rights such as being able to vote or run for public office.

Although the pardoning power is considered broad, it is not limitless. For example, a president can only issue pardons for federal (national-level) crimes.

The issue is relevant because there is a question mark over the sentencing of Trump in his hush-money case in New York. He will be unable to pardon himself in that state-level case when he returns to the White House in January.

There is a long-standing precedent of US presidents on both sides of the political divide issuing pardons – including to people close to them. This is the 26th pardon issued by Biden, a Democrat.

In 2020, Trump, a Republican, pardoned Charles Kushner, the father-in-law of his daughter Ivanka. Kushner was sentenced to two years in prison in 2004 for charges including tax evasion, campaign finance offences and witness tampering.

And in 2001, Bill Clinton, pardoned his younger half-brother, Roger Clinton, for a cocaine-related offence that dated back to 1985.

In both cases, the pardons were given to people who had already served a sentence. President Biden’s intervention in his son’s case comes before sentencing.

Trump granted 237 acts of clemency during his four years in the White House, according to the Pew Research Center, comprising 143 pardons and 94 commuted sentences. Many were in a flurry before he left office.

That number is significantly fewer than his predecessor Barack Obama, who during his eight-year stint granted 1,927 acts of clemency, according to Pew. These were 1,715 commutations and 212 pardons.

Most of those who received executive clemency under Obama had been convicted of narcotics charges at the height of the so-called US war on drugs.

One of the most controversial presidential pardons was granted by Gerald Ford to his predecessor Richard Nixon in 1974 – covering acts that occurred during the Watergate Scandal. It was described as an effort to heal the nation.

The day after he took office in 2021, Biden emphasised that he would do things differently to Trump. His press secretary told reporters that the flurry of last-minute pardons issued by Trump was “not a model… for how President Biden would use his own power. He would use his own power far more judiciously”.

Biden said after his son’s conviction that he would not issue a pardon. In the statement announcing his U-turn, he acknowledged that he had pledged to “not interfere with the justice department’s decision-making”. But, he said, the younger Biden had been “singled out” and subjected to a “miscarriage of justice”.

Trump is among those who have attacked Biden for the move, calling it an “abuse”.

The incoming president asked whether Biden would also pardon supporters of his who were prosecuted over the US Capitol riot on 6 January 2021.

Trump, who faced a series of legal issues while away from the White House, has repeatedly made the allegation that the US justice system has been weaponised against him and his supporters.

He has promised to issue pardons of his own for those who rioted in Washington. But who exactly will be granted clemency, and whether pardons will extend to those convicted of the most serious and violent offences, is still an open question.

The special counsel overseeing both cases, David Weiss, has flatly rejected claims that the younger Biden was singled out because of his family background.

“There was none and never has been any evidence of vindictive or selective prosecution in this case,” Mr Weiss’ team wrote in a court filing on Monday.

US First Lady Jill Biden said on Monday from the White House: “Of course I support the pardon of my son.”

The president’s decision sparked furious reaction from Trump and other top Republicans, who have long accused the Biden administration of “weaponising” the justice department against their enemies.

House of Representatives Speaker Mike Johnson said that “trust in our justice system has almost been irreparably damaged by the Bidens and abuse of it”.

House oversight committee chairman James Comer said Biden had “lied from start to finish about his family’s corrupt influence peddling activities”.

Criticism from Democrats – who have regularly accused Trump of disregarding the rule of law – was more muted.

“President Biden’s decision put personal interest ahead of duty and further erodes Americans’ faith that the justice system is fair and equal for all,” Colorado Senator Michael Bennet posted on X, formerly Twitter.

Congressman Greg Stanton, an Arizona Democrat, rejected Biden’s claim that the case was unfair.

“This wasn’t a politically motivated prosecution,” he said. “Hunter committed felonies and was convicted by a jury of his peers.”

Others defended the president.

Among them was Texas Democrat – and former defence lawyer – Jasmine Crockett, who told BBC Newshour that she believes that “we would be hard pressed” to find prosecutions similar to the younger Biden’s across the US.

“Let me be clear – this is a father and a president who did not only what was right by his son, but also did right to basically correct what I would consider a wrong,” she said.

Neama Rahmani, a former federal prosecutor, told the BBC that he believed Biden had misled the American people.

“President Biden was disingenuous this entire time when he said that he would not pardon his son,” Mr Rahmani said.

“A pardon was the plan from the beginning, but President Biden misled the American people because he, then Kamala Harris, were in the middle of an election.”

When he takes office in January, Trump will not be able to rescind his predecessor’s pardon, said Mr Rahmani.

The president’s power to pardon people is “absolute”, he said.

“There is nothing Donald Trump or the Republicans can do to stop it,” Mr Rahmani added.