PRESIDENT DONALD TRUMP and Democratic challenger Joe Biden concentrated their election campaigning on battleground states both see as critical to clinching an Electoral College victory.

Biden went to Florida to court the elderly, looking to deliver a knockout blow in a state Trump needs to win while trying to woo a group whose support for the president has slipped.

And Trump visited Pennsylvania, arguably the most important state on the electoral map, unleashing fierce attacks on Biden’s fitness for office in his opponent’s backyard.

“He’s shot, folks. I hate to tell you, he’s shot,” the president told a big rally crowd in Johnstown, saying there was extra pressure on him to win because Biden was the worst presidential candidate of all time.

“Can you imagine if you lose to a guy like this? It’s unbelievable.”

In his second rally since contracting the coronavirus, Trump spoke for more than an hour to a crowd of thousands packed in tightly and mostly maskless.

Thank you, Florida! pic.twitter.com/liQYRmvY7J

— Joe Biden (@JoeBiden) October 14, 2020

Like the night before in Florida, Trump seemed healthy, and his rhetoric on the pandemic — including the dubious claim that it was mostly a thing of the past — changed little despite his own illness, except for his threat to kiss audience members to prove his immunity.

Trump made a local pitch, hammering home the claim that a Democratic administration could limit fracking in areas where the economy is heavily dependent on energy, despite Biden’s proposal to only bar new leases on federal land, a fraction of US fracking operations.

Touting his elimination of a federal rule that would have brought more low-income housing to the suburbs, he also zeroed in on groups whose support he has struggled to retain, including female voters turned off by his rhetoric.

“So I ask you to do me a favour. Suburban women: Will you please like me? Please. Please. I saved your damn neighbourhood, OK?” Trump said.

“The other thing: I don’t have that much time to be that nice. You know, I can do it, but I gotta go quickly.”

Biden spent the day in Florida, his third visit to the state in a month, looking to expand on his inroads with older voters.

To the president, “you’re expendable, you’re forgettable, you’re virtually nobody,” Biden said at a centre for the elderly in Pembroke Pines.

The “only senior Donald Trump seems to care about” is himself, Biden added.

Biden also held a drive-in rally designed to promote voter mobilisation in the heavily African American community of Miramar.

“I’m running as a proud Democrat, but I will govern as an American president,” Biden said to supporters blaring their horns as they listened from cars.

“I’ll work as hard for those who vote against me as those who vote for me.”