Atlanta (AFP) - The volatile, dramatic US presidential race between Kamala Harris and Donald Trump headed to an unpredictable finish Tuesday, with millions of Americans casting their votes in one of the tightest elections of modern times.

The result – which may be known overnight or not for days – will bring major consequences, either making Harris the first woman in arguably the world’s most powerful job or handing power back to Trump and his nationalist “America First” agenda.

As voters formed long lines across the country, several bomb threats were reported at polling stations, while police at the US Capitol – where Trump’s supporters rampaged following his 2020 defeat – arrested a man who smelled like fuel and was carrying a flare gun.

Both the FBI and Georgia secretary of state Brad Raffensperger said the bomb threats, while not credible, appeared to originate from Russia.

In a possible preview of election challenges, Trump took to social media to say there is “talk about massive cheating” in Philadelphia, the Democratic stronghold of crucial state Pennsylvania.

City Commissioner Seth Bluestein, a Republican, responded on X that there was “absolutely no truth” to the charge, calling it “disinformation.”

Polls for weeks have shown a razor-thin race between Democratic Vice President Harris and Republican Trump, 78, who would be the oldest president at the time of inauguration, the first felon president and only the second to serve non-consecutive terms.

The Harris campaign reported strong turnout in Philadelphia including among Puerto Ricans, who were disparaged by a comedian at a Trump rally a week earlier.

An early exit poll by NBC News showed that the most important issue for voters was democracy – a signature issue for Harris – even more than the economy.

Harris, 60, would also be only the second Black and first person of South Asian descent to be president.

Harris made a late, dramatic entrance into the race when President Joe Biden dropped out in July, while Trump – twice impeached while president – has since ridden out two assassination attempts and a criminal conviction.

After criss-crossing the country, Harris returned to Washington where she called in to radio stations in swing states and took a few calls personally at a phone bank for voters.

“We’ve got to get it done. Today is voting day, and people need to get out and be active,” Harris told Atlanta station WVEE-FM.

She described her opponent as “full of vengeance. He’s full of grievance. It’s all about himself.”

- ‘If it’s a fair election’ -

Trump voted in Florida near his Mar-a-Lago residence, saying he felt “very confident” and that he wanted to be “very inclusive.”

Hours before his claims of fraud in Philadelphia, Trump said, “If it’s a fair election, I would be the first one to acknowledge it,” he said.

Casting a ballot in Arizona, Trump backer Camille Kroskey, 62, said she was voting in person due to concerns about voting fraud.

“I want to make sure I drop my ballot where it’s going to actually land somewhere,” she told AFP.

“Now, will it get counted?” she asked. “I don’t know.”

In Pennsylvania, Harris voter Marchelle Beason, 46, said the lines were “way, way, way more” than in the last election.

“We’re so divided right now, and she’s about peace. And everything that her opponent has to say is really negative,” she added.

- Major consequences -

At the same school, 56-year-old Darlene Taylor, wearing a homemade Trump shirt, said her main issue is to “close the border.”

Trump has vowed an unprecedented deportation campaign of millions of undocumented immigrants if elected.

The election is being watched closely around the world including in the war zones of Ukraine and the Middle East.

Harris has vowed to keep up support for Ukraine against Russia’s invasion and to put a greater effort in ending the Gaza war, although she has also voiced support for Israel.

Trump has promised a quick end to the Ukraine war, likely by pressing Kyiv into concessions, and has made clear he will give freer rein to Israel, which relies on US support.

Harris has hammered home her opposition to Trump-backed abortion bans in multiple states – a vote-winning position with crucial women voters.

Control of Congress is also at stake, with Republicans widely expected to win back control of the Senate.

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