– Updated

Former US president Donald Trump has described his arraignment on charges of trying to overturn the 2020 election as a “very sad day for America.”

“This is a persecution of a political opponent. This was never supposed to happen in America,” Mr Trump said before boarding his plane to return to New Jersey after his court hearing in Washington.

Mr Trump pleaded not guilty on Thursday (local time) to federal charges that he orchestrated a plot to try to overturn his election loss in what US prosecutors call an unprecedented effort by the then-president to undermine the pillars of American democracy.

The frontrunner for the 2024 Republican presidential nomination, entered his plea in a Washington courtroom just a kilometre from the US Capitol, the building his supporters stormed on January 6, 2021, to try to stop Congress from certifying his defeat.

The plea kicks off months of pretrial legal wrangling that will unfold against the backdrop of the presidential campaign, in which Mr Trump is seeking a rematch against Democratic President Joe Biden.

In a 45-page indictment on Tuesday, Special Counsel Jack Smith accused Mr Trump and his allies of promoting false claims the election was rigged, pressuring state and federal officials to alter the results and assembling fake slates of electors to try to wrest electoral votes from Mr Biden.

Mr Smith sat in the front row as Mr Trump, wearing his usual blue suit and red tie, entered his plea before US Magistrate Judge Moxila Upadhyaya. Mr Trump sat with his hands folded while awaiting the judge’s entry.

Mr Trump, 77, faces four counts, including conspiracy to defraud the US, to deprive citizens of their right to have their votes counted and to obstruct an official proceeding. The most serious charge carries a maximum prison sentence of 20 years.

Mr Trump has portrayed the indictment, as well as the other criminal cases against him, as a “witch hunt” intended to derail his White House campaign. In a series of social media posts since Tuesday, he has accused the Biden administration of targeting him for political gain.

“I NEED ONE MORE INDICTMENT TO ENSURE MY ELECTION!” he wrote on his Truth Social media platform ahead of his court appearance.

Third indictment in four months

Mr Trump has pleaded not guilty to other federal charges that he retained classified documents after leaving office and New York state charges that he falsified documents in connection with hush money payments to a porn star.

He may soon face more charges in Georgia, where a state prosecutor is investigating his attempts to overturn the election there. The Atlanta-area prosecutor, Fani Willis, has said she will file indictments by mid-August.

Presidential campaign rolls on

Despite his legal entanglements, Mr Trump leads a field of rivals seeking the 2024 Republican nomination.

Polls show Florida Governor Ron DeSantis in a distant second among Republican voters, many of whom have embraced Mr Trump’s assertion that he is the victim of a Democratic witch hunt.

Mr Trump’s standing with Republican voters has risen since his first indictment earlier this year in New York. But his legal woes are weighing on his support among independent voters, some 37 per cent of whom told a July Reuters/Ipsos poll they were less likely to vote for him in the general election as a result of the indictments.

The vast majority of Republican leaders, including several competing with Mr Trump for the White House, have either defended him or avoided direct criticism, instead accusing the Biden administration of weaponising the US Justice Department against a political foe.

Many of the allegations in Tuesday’s indictment had been well documented in media reports and the investigation conducted by a US House select committee.

But the indictment featured some details that were not widely known, including several based on grand jury testimony and contemporaneous notes from former vice-president Mike Pence, who is also running for the Republican presidential nomination.

The indictment describes a phone call in which Mr Pence told Mr Trump there was no legal basis for the theory that Mr Pence could block certification of the election.

“You’re too honest,” Mr Trump responded, according to prosecutors.

Although Mr Pence repeatedly told Mr Trump he lacked the authority to reject electoral votes from certain states, Mr Trump kept repeating the claim.

On January 6, as he spoke to his supporters before they attacked the Capitol, Mr Trump said: “If Mike Pence does the right thing, we win the election.”

Some rioters at the Capitol later chanted, “Hang Mike Pence!”

Mr Pence was one of the few prominent Republicans to criticise Mr Trump on Tuesday, saying that “anyone who puts himself over the Constitution should never be president”.

-AAP