With election day just 21 days away, President Donald Trump and Democratic challenger Joe Biden concentrated on battleground states they both see as critical to clinching an Electoral College victory.

US President Donald Trump and Democratic presidential nominee Joe Biden during the first 2020 presidential campaign debate in Cleveland, Ohio. September 29, 2020.
US President Donald Trump and Democratic presidential nominee Joe Biden during the first 2020 presidential campaign debate in Cleveland, Ohio. September 29, 2020. (Reuters)

US President Donald Trump has told a Pennsylvania crowd that he's fighting "Marxists" and "lunatics", while his Democratic challenger Joe Biden has accused him in Florida, another key electoral state, of having treated Americans as "expendable" during the Covid-19 pandemic.

With only 20 days until the November 3 election and badly down in the polls, Trump fired just about every insult about the Democrats and about Biden's mental state that he has in his arsenal.

He said Biden was "choking like a dog" during their televised debate, called him mentally "shot" and claimed the Democratic frontrunner was the pawn of communists.

"He is handing control to the socialists and Marxists and left-wing extremists," Trump told the large, raucous crowd in Johnstown. "He can't stand up to the lunatics running his party."

Going even further on his long-running narrative that 77-year-old Biden is too frail for the presidency, Trump, 74, tweeted a faked picture purporting to show Biden in a wheelchair, surrounded by elderly wheelchair-bound people in a room.

"Biden for president," the caption said, with "p" struck out to change the word to "resident ."

The mocking presentation of the infirm elderly was somewhat surprising given the president's growing problems in retaining the loyalty of seniors, an important electoral force.

'Crush the virus' 

In Johnstown, Trump reprised the outsider image that he developed for his surprise 2016 victory, telling the crowd that he was combating a "selfish and corrupt political class" back in Washington.

"This will end up being a large-scale version of Venezuela if they get in," he said, painting an anti-immigrant vision of a country where Democrats give free hospital care to "illegal aliens" while "decimating Medicare and destroying your social security".

The coronavirus, which has claimed more than 215,000 lives in America, was largely an afterthought, even if Trump himself was hospitalised for three nights after testing positive at the start of October.

"We're going to crush the virus very quickly.

It's happening already," Trump said, despite a swath of the United States now reporting large increases in infections.

"Soon it's going to be perfecto," he said.

READ MORE: Trump makes first public appearance since Covid-19 diagnosis

'Erratic' president 

Hours earlier, Biden was in Florida holding one of the much smaller events typical of his low-key campaign, zooming in on Trump's handling of the pandemic.

Arguably even more important on election day than Pennsylvania, Florida is a battleground state that Trump won in 2016 but where polls currently show Biden ahead.

Biden courted the elderly, telling an event at a retirement centre in Pembroke Pines, north of Miami, that Trump has "never been focused on you."

"His handling of this pandemic has been erratic, just like his presidency has been," he said.

Biden recalled that Trump once remarked that the virus – which has taken a particularly brutal toll among the elderly – "infects virtually nobody."

"You are expendable, you are forgettable, you are virtually nobody. That's how he sees this," said Biden, who, unlike Trump, wore a face mask throughout his remarks.

Trump was also in Florida on Monday night for his first rally since recovering from his bout with Covid-19.
This week, he will be heading out to Iowa and North Carolina, then back to Florida and Georgia.

READ MORE: Trump declares himself immune to Covid-19

Swing states 

Iowa and Georgia were two states which Trump won handily in 2016 but polls show tight races in both three weeks ahead of the November 3 election.

And a poll of likely Florida voters released on Tuesday by Florida Atlantic University (FAU) gave Biden a 51 percent to 47 percent lead there.

"Joe Biden continues to be competing better for senior voters than Hillary Clinton did in 2016, and that could be the difference in Florida," said Kevin Wagner, a political science professor at FAU.

Forty-four percent of those polled said Trump's handling of the coronavirus crisis was good or excellent, while 50 percent said it was poor or terrible.

Trump has brushed aside the polls, calling them "fake".

Texas, meanwhile, became the latest state to start early voting, which has been taking place at a record pace so far in the states that allow it, according to Michael McDonald, a professor at the University of Florida who tracks early voting.

According to McDonald's US Elections Project, voters have cast 11.86 million ballots so far in the states that report early voting.

READ MORE: Trump back in Oval Office, says 'I feel great'

Source: AFP