President Donald Trump cast his vote Saturday in Florida ahead of another punishing day with three campaign rallies as he works to close the gap with Joe Biden and pull off a 2016-style upset win on November 3.

"I voted for a guy named Trump," he said, flashing a smile after removing his black mask upon emerging from a polling station in West Palm Beach, not far from the Mar-a-Lago resort he officially made his home last year.

He thus became one of nearly 55 million Americans to cast early ballots in a year when the coronavirus has made in-person voting problematic.

"It was a very secure vote. Much more secure than when you send in a ballot, I can tell you that," said Trump, who insists without giving evidence that mail-in voting leads to fraud.

Continuing his frenetic pace, the president was to hop-scotch later in the day from North Carolina to Ohio to Wisconsin -- returning to the White House only minutes before midnight -- as he works furiously to make up lost ground. 

But the president's efforts have been inescapably overshadowed by a grim reality seized on by Biden: the US set a daily record for new Covid-19 cases on Friday, at nearly 83,000, with a further surge expected as cold weather arrives.

"That's Donald Trump's presidency," Biden said Saturday during a drive-in rally, one of two events planned for the day in his native Pennsylvania, a critical swing state. He spoke from a stage decorated with bales of hay and Halloween pumpkins.

"Yesterday (was) the worst day we've ever had," said Biden, who has been more restrained than Trump in his campaigning, and pandemic-conscious.

"At the debate on Thursday night Donald Trump said, and is still saying, we're rounding the corner. It's going away. We're learning how to live with it."

Biden added: "What I told him at that debate, we're not learning how to live with it. You're asking us to learn how to die with it and it's wrong."

The Biden campaign was also deploying a key surrogate, former president and former Biden boss Barack Obama, to speak later in the day in Miami. 

Biden has a firm lead in national polls, and narrower leads in many battleground states like Florida that typically decide the winner of US presidential elections.

The drama of the final Trump-Biden televised debate on Thursday was thought unlikely to move the needle significantly.

But Democrats are not about to forget the stunning upset Trump pulled off in 2016 when he defeated the favorite Hillary Clinton.

The president's current grueling travels aim to repeat that feat.

On Friday, Trump targeted the politically powerful seniors' vote in Florida, telling a crowd at the retirement community The Villages that all Biden talks about is "Covid, Covid, Covid" to "scare people."

"We're going to quickly end this pandemic, this horrible plague," he said.

In fact, the virus has claimed more than 224,000 American lives, with no end in sight.

Referring to Biden's warning of a "dark winter" ahead, Trump insisted the country is instead "approaching the light at the end of the tunnel."

He then pivoted to his own scare tactics, claiming that Biden would let in hordes of illegal immigrants including "criminals and rapists and even murderers."

Lack of leadership

While Biden has waged a lower-key campaign, even the 77-year-old Democrat is ramping up activity in the final stretch.

In his home state of Delaware on Friday, he gave a speech about economic recovery from the pandemic, slamming Trump's record and vowing -- as Trump has -- that he would provide a safe coronavirus vaccine to all who want it.

"We are more than eight months into the crisis and the president still doesn't have a plan," Biden claimed. "He's given up. He quit on you, on your family, on America.

Pivot too late? 

Trump's campaign has been turned upside down by the coronavirus crisis, which a majority of voters say he has handled poorly.

In addition to the national disaster, Trump's reelection bid has been hampered throughout by his own erratic and often bad tempered behavior.

At Thursday's final televised debate in Nashville, the president pivoted to the more even-keeled leader that aides have long been hoping Americans will see.

But whether this shift from the usually bruising diet of insults, grievances and conspiracy theories will be enough at this point is an open question.

Trump seized during the debate on Biden's vow to "transition" away from the heavily polluting oil industry -- potentially a wounding admission in petroleum-producing states like Pennsylvania and Texas. 

But Biden himself scored points by raising questions about Trump's holding of a bank account in China and his failure to publish his tax returns.