ST. PETERSBURG, FL -- Mitt Romney continued to drive a debt-oriented message here on Wednesday morning, extending his "prairie fire" of debt metaphor with the assistance of a prop.

In a nod to the independent voters who pushed the Sunshine State into the Democratic column in 2008, Romney noted that both parties were responsible for pushing the debt to the "incomprehensible" levels – which were represented on a giant prop debt clock behind him.

Mary Altaffer / AP

Republican presidential candidate Mitt Romney speaks at a campaign stop May 16 in St. Petersburg, Fla.

"There was another area during [President Obama's] campaign, he said he would focus on. You see, he was very critical of his predecessor for the debts his predecessor put in place. And sure it's true you can't blame one party or the other for all the debts this country has, because both parties in my opinion have spent too much and borrowed too much when they were in power," Romney said in this key swing state.

(Interestingly, Romney danced around the actual name of that predecessor, George W. Bush, who on Tuesday endorsed the former Massachusetts Governor when asked a question by an ABC News reporter.)

"[President Obama] was very critical of his predecessor because the predecessor put together $4 trillion of debt over eight years," Romney continued. "This president however - oh by the way, he said that doing that was unpatriotic, irresponsible and unpatriotic. And he said he would cut the debt in half if he became president. Instead he doubled it, alright, he doubled it."

Democrats answered those charges quickly.

“In Florida today, Mitt Romney continued to make dishonest claims- both about President Obama’s record and his own," Obama spokesperson Lis Smith said in a statement. “While President Obama has put forward a plan to reduce the deficit by more than $4 trillion by making responsible spending cuts and asking every American to pay their share, Mitt Romney refuses to say what spending cuts or tax increases he’d make to cover the cost of giving $5 trillion in tax breaks to the wealthiest Americans. Mitt Romney simply wants to return to the same policies that caused the economic crisis and weakened the middle class."

Meanwhile, Romney used his prop clock like a battering ram against the president.

"Gosh, when we put that clock up, we made that clock back in the New Hampshire primary days and it began with 14 back then. Now its fifteen, six eighty five, it'll be sixteen coming soon. It is not at all what he promised," Romney said. "This presidency has been a disappointment, and the people who have been hurt by this disappointment are the American people."

The presumptive Republican nominee did not mention his plan to reform entitlements here in senior-heavy Florida, but repeat his plans to increase military spending -- a portion of Romney's fiscal vision not easily squared with his plans to cut spending broadly.

"I'd like to take shipbuilding from 9 to 15 a year, by the way that will help put people to work. And I want to buy more aircraft and I want to have more active duty personnel and I want to make sure we give our veterans the care they richly deserve," Romney said.