Donald Trump last week turned his New York fraud trial into a political circus and a platform for his election campaign while Joe Biden struggled to persuade voters that they’re wrong about the economy.

Trump engineered a parade of leading Republicans to demonstrate their allegiance outside the courthouse in downtown Manhattan even as his trial laid bare the swamp that is the former US president’s professional and personal life.

Meanwhile, Biden has spent the trial trying to get Americans to pay attention to his claim to have done much more for the economy than Trump ever managed, even though polls show many voters do not believe it.

Trump has been obliged to sit in silence through his trial for allegedly falsifying business records to claim that $130,000 in hush money paid to the porn star Stormy Daniels before the 2016 election, after she claimed to have had sex with the then businessman a decade earlier, were legal expenses. A gag order has forced Trump to curb his natural inclination to attack the judge, the judge’s family, the prosecutor and the leading witness against him, his former lawyer Michael Cohen.

But Trump worked his way around the order, while demonstrating the strength of his grip on the Republican party, by summoning a parade of Washington politicians to stand in front of the court and say what he could not.

Some had their strings yanked with hints that their names are in the pot of potential vice-presidential candidates. Others calculated that it was good politics to make sure constituents know they remain loyal to Trump

JD Vance, the US senator and bestselling author who is reputedly a leading contender for the vice-presidential slot despite once having described Trump as “an idiot”, made an appearance on Monday to back the former president’s claim that the trial is an attempt to stop him running against Biden.

“What’s going on inside that courtroom is a threat to American democracy,” he declared.

Vance later described the case against Trump as a “paperwork violation” and said he was “convinced the main goal of this trial is psychological torture”.

The US senators Tommy Tuberville and Rick Scott of Florida joined the parade of genuflecting politicians along with the governor of North Dakota and the attorneys general of Texas, Alabama and Iowa.

But the prize for Trump was surely the arrival of Mike Johnson, the speaker of the House of Representatives, one of the most powerful people in Washington. Johnson rode to court in Trump’s motorcade and then told the world that the prosecution was a “sham” and that Cohen was “on a mission for personal revenge”.

“No one should believe a word he says in there,” he said.

Inevitably, the former president could not resist belittling those who did his bidding while celebrating his defiance of the judge’s order.

“I do have a lot of surrogates, and they are speaking very beautifully,” he said.

Meanwhile, with Trump in the dock, Biden has been trying to shift attention to his claim to have revived the US economy.

The president taunted his predecessor earlier this month by visiting an empty Wisconsin field where Trump once waved a golden shovel and announced construction of the “eighth wonder of the world”, a huge electronics factory by the Taiwanese company Foxconn that would have created 13,000 jobs. But even though Trump’s administration spent more than $500m to pave the way for the project, including bulldozing scores of homes and farms, it was never built.

The site in Racine sat barren for years, an embarrassing reminder of Trump’s failed promises. Biden stood on the same spot and announced that Microsoft will spend $3bn to construct an artificial intelligence datacenter in Racine, bringing thousands of jobs.

It was a political stunt intended to highlight that Biden has done more to create jobs and improve the economy than Trump. The problem for the president is that the voters don’t feel it.

A recent Financial Times poll found that 58% of voters disapproved of Biden’s handling of the economy. Just 28% said the president improved it.

While Biden can claim to have created more manufacturing jobs, to have invested in ramping up tech manufacturing and to have spent more than his predecessor on renewing the US’s ageing roads, bridges and other infrastructure, most voters say they are primarily concerned about inflation. Large numbers of Americans continue to barely scrape by financially. Rising prices have forced more deeper into debt, and healthcare companies continue to take a bigger chunk of workers’ pay even as their medical insurance pays an ever small slice of the bill.

Biden’s response is to say the numbers are wrong.

“We’ve already turned it around … the polling data has been wrong all along,” he told CNN.

Biden’s campaign is instead putting its faith in a different set of numbers.

As expected, Trump won with nearly 80% of the vote in the Republican presidential primary in Maryland on Tuesday. But Nikki Haley took more than 20% even though she dropped out of the race more than two months ago. Similar results in other swing state primaries, including Wisconsin, Georgia and Michigan, could be bad news for Trump even though polls say he is ahead in most of them.

The Democrats think that for all Trump’s bluster, the trial reminds voters of his considerable personal shortcomings and that is having an impact.

The Biden campaign has latched on to a poll last month showing that a majority of Republicans who voted for Haley in the primaries said they would not support Trump in November. The campaign claims that could be enough to ensure Trump’s defeat.

Meanwhile, Cohen will be back in court on Monday to face further cross-examination about his testimony that Trump told him to pay $130,000 to buy Daniels’s silence ahead of the 2016 election.

Trump’s lawyer, Todd Blanche, who was until recently a registered Democrat, accused Cohen of lying about the transaction and of trying to profit from turning on the former president.

Cohen certainly made no secret of his distaste for Trump. Asked if he wanted to see the former president convicted in the case, Cohen said he did.

Blanche asked Cohen if he had called Trump a “boorish cartoon misogynist” and “Cheeto-dusted cartoon villain”?

“Sounds like something I would say,” Cohen replied.