David Jackson, and Gregory Korte

USA TODAY

MIAMI — The 2016 presidential campaign has been marked by an epic, historic political rivalry — and not just the one between Donald Trump and the Clintons.

The one between Trump and Barack Obama.

In many ways, Trump's unorthodox, aggressive presidential campaign is driven by antipathy toward Obama. The president, in turn, has campaigned harder than any president not running for re-election in recent memory in his aggressive bid to stop Trump from winning the opportunity to dismantle his legacy.

After Obama deemed Trump "unfit" for the presidency during an August news conference, Trump retorted on Twitter that Obama "will go down as perhaps the worst president in the history of the United States!"

And so it seemed only fitting that, with just five days left until Election Day, their paths would cross in the pivotal state of Florida, where both men have been devoting an increasing share of their time. Trump's plane and Air Force One were both parked at the Miami airport Wednesday and Thursday, and Obama's Miami hotel overlooked the venue where Trump spoke on Wednesday.

Even Trump took note of the fact that Obama seemed to be shadowing him. "Looking at Air Force One" in Miami, he tweeted Thursday. "Why is he campaigning instead of creating jobs & fixing Obamacare? Get back to work for the American people!"

White House Deputy Press Secretary Eric Schultz dismissed any notion Thursday that there was a connection between the location of the Trump and Obama events.

“It’s probably a function of the winnowing battleground map," he said.

Trump also criticized Obama over his campaign efforts at a later rally in Jacksonville.

“This guy ought to be back in the office working," Trump said of Obama, who also held a campaign event in Jacksonville Thursday. "He’s not going to be there very long, thank goodness."

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Michael Caputo, a former Trump campaign aide, said that while the New York businessman is more motivated these days by defeating the Democratic nominee, his initial inspiration was to "try to undo the damage" wrought by the Obama administration. "Obama is as much a motivation for his candidacy as Hillary Clinton," he said.

In rally after rally, Trump has pledged to "repeal" Obama's landmark health care law; to strike down a litany of Obama executive orders, particularly on immigration and energy production; and to kill the nuclear deal with Iran and the new diplomatic approach to Cuba. Trump has accused the president of being "the founder" of the Islamic State and brought the president's estranged half-brother to one of the debates with Clinton.

Seeking to link the president to the current Democratic nominee, Trump has vowed to end "the Obama-Clinton war on coal" and the "Obama-Clinton defense sequester." In Miami this week, as he has elsewhere, Trump told supporters that "the last thing we need is another four years of Obama."

For his part, Obama is playing the traditional role of the high-profile campaign surrogate by going on the attack.

During a Miami speech Thursday, the president blasted Trump's populist credentials.

“This is a guy who spent 70 years, his whole life, born with a silver spoon, showing no respect for working people," Obama said, adding that Trump had only surrounded himself with "working people" when they were "cleaning his room.”

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In North Carolina on Wednesday, Obama spent as much time talking about Trump as he did about Clinton. He called Trump a "con artist and a know-nothing" and said he was "temperamentally unfit to be commander in chief."

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The rivalry extends back to the years in which Trump pondered a a challenge to the president's 2012 re-election bid.

The real estate mogul and reality television star built a name in politics by becoming the de facto leader of the movement known as "birtherism," the false idea that Obama was not born in the United States.

The flap prompted Obama to produce a long-form birth certificate from Hawaii. The president also got back at Trump in a most public way, with pointed jabs at Trump during the 2011 White House Correspondents Association dinner.

As Trump sat in the audience, Obama riffed that nobody was happier than "The Donald" to have the birth certificate issue resolved so that "he can finally get back to focusing on the issues that matter — like, did we fake the moon landing? What really happened in Roswell? And where are Biggie and Tupac?"

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The president also mocked Trump's presidential pretensions at that dinner five years ago, saying the entertainment mogul "would bring some change to the White House." Video monitors showed a mock-up of the “Trump White House Resort and Casino.”

Within weeks, Trump announced he would not run for president in 2012. The idea obviously stuck with him, however, though Trump has denied that the rhetorical beating he took at that dinner was the impetus for his 2016 presidential bid.

Two-term presidents are often issues in the races to replace them. Obama himself attacked outgoing President George W. Bush during his initial bid in 2008, and Bush made President Bill Clinton one of the issues in the 2000 race.

The Trump-Obama rivalry, however, is notable for its mutual ferocity, as well as Trump's status as anti-establishment outsider willing to say just about anything.

"Clearly, Obama got under Trump's skin," said Stephen Hess, a presidential scholar at the Brookings Institution in Washington. "Obama is leaving after eight years and his legacy is hanging in the balance . ... This is very important for him."