NEW YORK – Workers erected barricades around a Manhattan courthouse on Monday as New York City braced itself for a possible indictment of former US president Donald Trump over an alleged hush-money payment to a porn star during his 2016 election campaign.

The barriers went up in preparation for what would be the first-ever criminal case against any former or sitting US president, two days after Mr Trump urged his followers on social media to protest against what he said was his looming arrest.

In his call for protests, he raised concerns for law enforcement that his supporters might engage in violence similar to the Jan 6, 2021, attack on the US Capitol in Washington.

Fearing a trap, however, several far-right grassroots groups have opted not to heed his call, security analysts said.

A grand jury, which heard further testimony on Monday, could bring charges this week for arranging payments to porn star Stormy Daniels. Mr Trump, who is seeking the Republican nomination for the White House again in 2024, had predicted he would be arrested on Tuesday.

On Monday, the grand jury heard from a witness, lawyer Robert Costello, who said Mr Trump’s former fixer Michael Cohen had handled the hush-money payments without the former president’s involvement.

“Michael Cohen decided on his own – that’s what he told us – on his own, to see if he could take care of this,” Mr Costello told reporters after testifying to the grand jury at Mr Trump’s lawyers’ request.

Mr Cohen, who testified twice before the grand jury, has said publicly that Mr Trump directed him to make the payments on his behalf.

An indictment could hurt Mr Trump’s comeback attempt. Some 44 per cent of Republicans say he should drop out of the presidential race if he is indicted, according to a seven-day Reuters/Ipsos poll that ended on Monday.

The investigation by Manhattan District Attorney Alvin Bragg is one of several legal challenges facing Mr Trump.

Mr Cohen pleaded guilty in 2018 to federal campaign finance violations tied to his arranging payments to Ms Daniels, whose legal name is Stephanie Clifford, and another woman in exchange for their silence about affairs they claimed they had with Mr Trump.

Mr Trump has denied that any such affairs took place.

No sign of unrest

New York Mayor Eric Adams told reporters that police were monitoring social media and keeping an eye out for “inappropriate actions” in the city. The City of New York Police Department said there were no known credible threats.

On Monday afternoon, police and two people carrying signs that said “Arrest Trump” and “Trump is Over” lingered on the courthouse steps.

If charged, Mr Trump would most likely have to travel from his Florida home for fingerprinting and other processing. Law enforcement officials met on Monday to discuss the logistics, several media outlets reported.

Sources have said Mr Bragg’s office was presenting evidence to a grand jury about a US$130,000 (S$174,000) payment made to Ms Daniels in the final weeks of the 2016 campaign.

Mr Trump’s fellow Republicans have widely criticised the probe as politically motivated.

Florida Governor Ron DeSantis, Mr Trump’s rival for the Republican presidential nomination, said on Monday that Mr Bragg was imposing a “political agenda” that compromised the rule of law, but he also took a veiled swipe at Mr Trump.

“I don’t know what goes into paying hush money to a porn star to secure silence over some type of alleged affair,” he told reporters.

Republicans in the US House of Representatives launched an investigation of Mr Bragg’s office with a letter seeking communications, documents and testimony related to the probe.

Mr Trump was impeached twice by the House during his presidency, once in 2019 over his conduct regarding Ukraine and again in 2021 over the attack on the US Capitol by his supporters. He was acquitted by the Senate both times.

Several legal challenges

Mr Bragg won a conviction last December against Mr Trump’s business on tax fraud charges.

But legal analysts say the hush-money case may be more difficult. Mr Bragg’s office will have to prove that Mr Trump intended to commit a crime, and his lawyers will most likely employ a range of counter-attacks to try to get the case dismissed, experts say.

Mr Trump, meanwhile, has to contend with other legal challenges, raising the possibility that he will have to shuttle between campaign stops and courtrooms before the November 2024 election.

His lawyers on Monday asked a court in the US state of Georgia to quash a special grand jury report detailing its investigation into his alleged efforts to overturn his 2020 statewide election defeat.

The filing in Fulton County Superior Court also seeks to have the county district attorney, Ms Fani Willis, recused from the case, arguing that her media appearances and social media posts demonstrate bias against Mr Trump.

Mr Trump is also seeking to delay a civil fraud trial, scheduled for Oct 2, brought by the New York attorney-general that alleges a decade-long scheme to manipulate the value of his assets to win better terms from bankers and insurers.

He faces two civil trials involving former magazine columnist E. Jean Carroll, who claims that he defamed her by denying he raped her. A federal judge on Monday denied a request from both sides to combine the two cases into one. BLOOMBERG