With five days to go until the election and time running out to sway undecided voters, President Barack Obama is stumping for Hillary Clinton on Thursday in the bitterly contested must-win state of Florida.

Republican Donald Trump will hold a rival rally in the city of Jacksonville just hours before Obama's event, highlighting both candidates' laser focus on Florida with the race tightening in its final days.

"Imagine it is January 20, 2017 and imagine that it is Donald Trump standing in front of the Capitol," she told a 15,000-strong crowd in Tempe, Arizona, triggering a chorus of boos for her Republican opponent.

"Imagine that he is taking the oath of office and then imagine that he is in the Oval Office making the decisions that affect your lives and your future," she said.

Clinton painted a picture of Trump as a president who demeans women, exacerbates racial divisions and is so thin-skinned and unpredictable that he could "start a real war instead of a Twitter war."

The note of caution was echoed by Obama, who warned voters that America's very future was at stake.

"The fate of the republic rests on your shoulders," he declared in North Carolina, one of a handful of swing states where the race will be decided.

"The fate of the world is teetering and you, North Carolina, are going to have to make sure that we push it in the right direction," Obama declared.

The 70-year-old Republican, by contrast, treated supporters in Florida to a now familiar tirade, predicting Clinton's downfall and vowing to "drain the swamp" of corruption in Washington.

Appearing at a triumphal rally in Pensacola, Trump also highlighted his need to stay on message and avoid the self-inflicted gaffes that have marred his White House run.

"Nice and cool. Right? Stay on point Donald, stay on point. No sidetracks Donald, nice and easy," he said.

Trump boasted that many opinion-makers and voters are now flocking to his standard.

"We're only left with one person, crooked Hillary Clinton. We're going to win. We're going to win."

Such talk -- partly supported by one poll on Tuesday showing him moving slightly ahead of Clinton -- has delighted America's foes, made its allies queasy and spooked financial markets.

Trump has been battered by scandals that would have sunk a less brazen showman: accused of sexual assault, of not paying taxes and of ties to Russia's Vladimir Putin and the mob.

But renewed FBI scrutiny of Clinton's use of a private email server when secretary of state has fired up the Republican's raucous fan base and fed doubts about the Democrat's trustworthiness.

'Downright embarrassing'

The dramatic tightening in the polls has convulsed financial markets worldwide in the past few days. The dollar slipped against the euro, while the Mexican peso -- sensitive to Trump's threat to build a wall on the country's border -- lost one percent.

This week, US Secretary of State John Kerry admitted the campaign has been "downright embarrassing" as he deals with America's friends and foes abroad, and the latter are in full voice.

Iran's supreme leader Ayatollah Ali Khamenei -- whose regime paints America as a comic-book foe -- crowed that the "catastrophic reality" of the candidates "goes beyond what even we were saying."

In Britain, a giant effigy of Trump wielding the head of his rival Clinton was to be burned during traditional November 5 bonfire night celebrations.

Long-shot bets

The long and often unedifying 2016 race is now being fought in a few corners of a few states, most notably Florida, Ohio and North Carolina.

These three states offer the best chance for both candidates to cross the winning threshold of 270 out of 538 electoral college votes.

But the two hopefuls have also placed some long-shot bets.

Clinton traveled to Arizona, which Democrats haven't won since 1996 when her husband Bill claimed the presidency by a landslide.

An Emerson poll on Wednesday had Clinton losing the state by only four percentage points, and both of its Republican senators oppose Trump, offering the prospect of a shock Clinton win.

Meanwhile, Trump campaigned in Wisconsin and Michigan, both traditionally Democratic states where polls show Clinton leading by six points or more.

But he spent most of Wednesday in Florida -- which is likely to make-or-break his presidential dreams -- and will remain there Thursday to build momentum.

jpegMpeg4-1280x720Both candidates are already planning for a favorable outcome on Election Night.

Trump's campaign said Wednesday its invitation-only "victory party" will be held at the Hilton Midtown hotel in New York, a short distance from Trump Tower.

Clinton has booked the glass-enclosed Jacob K Javits Convention Center, also in New York -- a wink to the "glass ceiling" she would be breaking as the first woman elected to the White House.