US President Barack Obama and his Republican rival, Mitt Romney, on Saturday began preparing for their final debate, with Obama hunkering down at Camp David and Romney staying in Florida.
The third and last of their debates is scheduled for Monday at Lynn University in Boca Raton, Florida.
On Friday, Obama set an aggressive tone accusing Romney of suffering from policy "Romnesia," a barb dismissed by the Republican as pettiness 18 days before the election.
One night earlier, both men had traded light-hearted banter at a charity dinner, but on Friday the verbal attacks turned nasty, with the Democratic incumbent taunting Romney's efforts to tack to the center as polling day looms.
"Mr. Severely Conservative wants you to think he was severely kidding about everything he said over the last year," Obama said at a rally attended by some 9,000 people at a university campus outside Washington.
The Obama camp's previous bid to skewer Romney with insulting tags -- such as pushing the Robin-Hood-in-reverse term "Romney Hood" to tarnish his tax policies -- have done nothing to protect the president's shrinking poll lead.
But, with the pair's last of three head-to-head debates set for Monday, the campaign returned to its tried and tested formula of branding Romney an untrustworthy flip-flopper.
"I mean, he's changing up so much and backtracking and sidestepping, we've got to name this condition that he's going through. I think it's called 'Romnesia.' That's what it's called," Obama told the crowd.
The Republican nominee meanwhile campaigned in the biggest political battleground of all, Florida, where Monday's debate will be held, and he didn't hesitate to strike back at the president's comments.
"They've been reduced to petty attacks and silly word games," Romney told a crowd of more than 8,500 people at Daytona Beach, adding that Obama's re-election bid "has become the incredible shrinking campaign."
"This is a big country, with big opportunities and great challenges, and they keep on talking about smaller and smaller things."
Romney, accompanied by his running mate Paul Ryan, laid into the incumbent for failing to map out his plan for another four years should he win re-election.
"They have no agenda for the future, no agenda for America, no agenda for a second term."
While Romney's camp dismissed Obama's taunt as a gimmick, the image of Romney as a flip-flopper, one that his fellow conservatives have hit him with in the past, might yet gain traction with undecided voters.
One source that definitely does not back the multimillionaire private equity baron is The Salt Lake Tribune, the local paper in the home city of Romney's Mormon faith, albeit a liberal one that endorsed Obama in 2008.
In an editorial, the paper lavished praise on Romney for saving the city's 2002 Winter Olympics, but said his subsequent courting of the right-wing Tea Party movement and refusal to detail his tax plan should rule him out.
"Romney has raised the most frequently asked question of the campaign: 'Who is this guy, really, and what in the world does he truly believe?'" it said.
"Politicians routinely tailor their words to suit an audience. Romney, though, is shameless, lavishing vastly diverse audiences with words, any words, they would trade their votes to hear."
While Obama was addressing crowds in Virginia, a state he won narrowly in 2008 but where Romney is making up ground, his Vice President Joe Biden flew to Florida, where three of the race's four main figures were stumping for votes.
Obama won both states in 2008, but as a measure of the tightness of this year's contest, the two are now up for grabs, with Florida leaning toward Romney, according to a widely-read poll average by website RealClearPolitics.
There, Romney won an endorsement from the Orlando Sentinel, whose editorial reflected a widely-held disappointment in Obama's handling of the economy.
"We have little confidence that Obama would be more successful managing the economy and the budget in the next four years," wrote the editors, who endorsed Obama in 2008.
On Monday night both men will be in the Sunshine State, in Boca Raton for a televised debate focused on foreign affairs.
Going into the campaign, Obama was seen as strong on foreign policy, thanks to his withdrawal of US troops from Iraq and decision to order a mission that killed Al-Qaeda kingpin Osama Bin Laden.
But Romney's camp has hammered the president on his handling of the Middle East, accusing him of neglecting ally Israel and of underestimating the threat of extremist passions unleashed by the Arab Spring revolts.