On the penultimate day of a tense US presidential contest that polls show is headed for a photo finish, Kamala Harris and Donald Trump started their final frantic campaign blitz Monday, targeting Pennsylvania, a must-win state.

Trump, 78, dismissed claims that he was physically and psychologically worn out by his advanced age and the demanding election schedule during his first event of the day in North Carolina.

“I’m not even sleeping. In a 90-minute, insulting stump speech that he has given several times in recent weeks, he declared, “I’ve seen 62 days without a day off.”

Harris offered a thumbs up and said she was “feeling good” as she boarded her jet to Allentown, Pennsylvania, for her first engagement of the day.

While Democrat Harris stated that “momentum” was in favour of her campaign to become America’s first female president, Republican Trump has pledged a “landslide” in his quest for a spectacular comeback to the White House.

However, the polls point to a stalemate both nationally and in the seven swing states where the outcome is anticipated.

With significant ramifications for Middle Eastern wars, Russia’s war in Ukraine, and the fight against climate change—which Trump has referred to as a hoax—the globe is breathlessly awaiting the conclusion.

If Trump loses, he is likely to reject the outcome, which may lead to political turmoil, social unrest, and violence, further testing US democracy.

“Donald Trump and his team are already hinting that they could announce their triumph too soon. Ian Sams, a spokesman for Harris, stated on Monday that “we fully expect him to.”

“To cast doubt on the nonpartisan election officials is a sign of weakness and concern that he might lose.”

The election is now down to Pennsylvania, the most contested battleground state, following a number of dramatic turns, including two attempts to assassinate Trump and Harris’ unexpected late entry.

Pennsylvania is the single largest swing state prize under the US Electoral College system, which distributes power according to population. Trump and Harris will have opposing rallies in Pittsburgh, an industrial metropolis.

Harris will campaign throughout the day throughout the state, ending with a Lady Gaga event in Philadelphia. From North Carolina, Trump will proceed to Pennsylvania and then Michigan.

More than 78 million people have already cast ballots, which is around half of the total number cast in 2020, and both parties think this early turnout is encouraging.

As the United States selects between two candidates whose ideologies could hardly be more dissimilar, the closeness of the 2024 White House contest represents a divided nation.

In his quest for a second term, former President Trump has intensified his use of aggressive and sinister rhetoric, making him the oldest major party candidate ever elected and the first convicted criminal.

Following President Joe Biden’s withdrawal from the contest in July, Vice President Harris, 60, has shot to the top of the Democratic ticket.

While Trump has concentrated on immigration and the economy and labelled political opponents the “enemy from within,” Harris hopes that abortion is a crucial topic that can harm Trump, particularly with female voters.

With boisterous rallies, podcast interviews to win over hesitant voters, and antics like Trump riding in a trash truck and Harris making an appearance on the comedy show “Saturday Night Live,” they have both been on a zigzag tour across the swing states.

Trump told supporters in the last days of the campaign that he wouldn’t mind if journalists were shot, made ludicrous claims of election fraud, and went into graphic detail about atrocities committed by illegal immigrants.

Harris declared during a boisterous rally in Michigan on Sunday that “we have momentum — it’s on our side” following some more positive recent polling.

Harris promised to do “everything in my power to end the war in Gaza” in an effort to win over Michigan’s sizable Arab-American population, which has criticised the US’s handling of the Israel-Hamas conflict.

Following his embarrassing remark last week that Trump’s followers were “garbage,” outgoing President Biden, 81, has been conspicuously missing from the trial.