Secret Service agents whisked Republican nominee Donald Trump off stage during a rally in Reno, Nevada, after someone in the crowd yelled "gun", adding drama in the final days of campaigning.
The two presidential candidates and their surrogates will be criss- crossing the country, cramming in just one more speech or one more handshake that could make the difference between a White House win and going home empty-handed.
Mr Trump was expected to cover at least 10 states before Election Day tomorrow, including New Hampshire, North Carolina and Pennsylvania; and squeezing in a last-minute 11pm rally in Michigan tonight.
Democrat Hillary Clinton and her top surrogates, including President Barack Obama and former president Bill Clinton, would be in states such as Ohio, Wisconsin and even Arizona - a traditional red state that the Democrats think they have a chance of flipping.
Her final event this evening will be in Philadelphia, Pennsylvania, where she will be accompanied by Mr and Mrs Obama, Mr Clinton and their daughter Chelsea.
At the Nevada rally on Saturday, the man who was thought to be a threat to Mr Trump was handcuffed and hastily escorted out of the venue by law enforcement.
Minutes later, Mr Trump was back on stage to finish his speech unfazed by the disturbance.
"Nobody said it was going to be easy for us," he said. "But we will never be stopped."
Secret Service agents later confirmed no weapon was found on the man, identified as Mr Austyn Crites. But the incident shows tensions are running high as over a year of campaigning comes down to the wire.
Mr Crites, who told reporters he was a Republican, said it all started when he raised a "Republicans Against Trump" sign. The crowd then turned on him and assaulted him, he added.
In Florida, Mrs Clinton showed her tenacity, finishing her speech despite the rain. As her clothes turned a darker green from the rain, she skipped to her closing lines.
"I want to be the president for everybody: Everybody who agrees with me, people who don't agree with me, people who will vote for me, people who don't vote for me," she said on Saturday, her voice hoarse from intense campaigning.
Later in the day, she was in Philadelphia, more than 1,500km away, sharing the stage with pop singer Katy Perry.
Entertainers from Beyonce, Jay Z to Jennifer Lopez and Stevie Wonder have hit the campaign trail for Mrs Clinton, and singer James Taylor was expected to do the same in New Hampshire yesterday.
Then it will be basketball star LeBron James' turn in Cleveland, Ohio, a state that is known to be a bellwether for the elections and seems to be leaning Republican at the moment.
As of Saturday, more than 40 million Americans have cast their votes, according to data from the United States Election Project.
Some media outlets have also reported that the Latino vote in Florida, Georgia and North Carolina is up from past elections.
According to CNN, citing statistics from data company Catalist, around this time in 2008, Latinos cast about 260,000 votes or 9.6 per cent of the early votes cast in Florida. This year, they make up about 596,000 or 14 per cent of the votes cast - a positive sign for the Democrats as Latinos are part of the coalition that delivered the win to Mr Obama in the past two elections.
At the moment, political website RealClearPolitics' average of polls shows Mrs Clinton ahead of Mr Trump by 1.2 percentage points in Florida - another important battleground state with 29 electoral college votes.
In the national average, she is clinging on to a 2 percentage point lead over her opponent.
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