"American taxpayers are on track to lose $25 billion as a result of President Obama's handling of the auto bailout, and GM and Chrysler are expanding their production overseas," said an e-mailed statement issued in the name of running mate Paul Ryan.
The two storms were at opposite ends of a race nearing its end in a flurry of early balloting by millions, unrelenting advertising, and so many divergent polls that the result was confusion, not clarity.
National surveys make the race a tight one for the popular vote, with Romney ahead by a statistically insignificant point or two in some, and Obama in others.
Both sides claim an advantage from battleground-state soundings that also are tight. Obama's aides contend he is ahead or tied in all of them, while Romney's team counters that his campaign is expanding in its final days into what had long been deemed safe territory for the president in Michigan, Pennsylvania, and Minnesota.
The storm added yet another element of uncertainty, as Obama spent a third day embracing his role as incumbent and Romney tried to tread lightly during a major East Coast disaster.
On Wednesday, Romney affirmed support for federal disaster aid after he was asked for comment on his past comments seeming to downplay a federal role.
"Every time you have an occasion to take something from the federal government and send it back to the states, that's the right direction," Romney said at a debate last year. "And if you can go even further, and send it back to the private sector, that's even better."
On Wednesday, the Romney campaign reassured the public it supports a strong program of storm relief.
"I believe that FEMA plays a key role in working with states and localities to prepare for and respond to natural disasters," the Romney statement said. "As president, I will ensure FEMA has the funding it needs to fulfill its mission. . . ."
Campaigning in Tampa, Romney said: "We love all of our fellow citizens. We come together at times like this, and we want to make sure that they have a speedy and quick recovery from their financial and, in many cases, personal loss."
His criticism of Obama was glancing. "I don't just talk about change. I actually have a plan to execute change and make it happen."
Romney was spending a full day in the state, campaigning with former Gov. Jeb Bush. It was an unusual commitment of time in the final days of a close race.
The debate was ferocious over Romney's broadcast ads. The radio version said that after Obama's auto bailout, GM has "cut 15,000 American jobs, but they are planning to double the number of cars built in China, which means 15,000 more jobs for China.
"And now comes word that Chrysler is starting to build cars in, you guessed it, China."
Both GM and Chrysler have taken issue with the ads, emphasizing that they are not sending jobs abroad that would otherwise employ Americans.
Chrysler is adding 1,100 jobs to its plant in Toledo. It is also adding production facilities in China as demand for cars there grows. Because of trade rules, it is easier for companies to build cars for the Chinese market in China. It's also more efficient. Japanese automakers, for example, have plants in the United States to meet American demand.
Ryan's e-mailed response conceded nothing. "President Obama has chosen not to run on the facts of his record, but he can't run from them," it said.
His reference to a $25 billion cost to taxpayers reflected the Treasury Department's most recent estimate of the amount GM and Chrysler still owe the government from the financing it received during a managed bankruptcy in 2009.
In the race's final days, Romney's campaign and supporters aired ads in Minnesota and Pennsylvania, two states long considered safe for the president. Allies also are airing commercials in Michigan and New Mexico.
Obama's aides insisted the states were safe for him, but it dispatched former President Bill Clinton to Minnesota, and purchased airtime in the three other states to respond to the Republicans.
Obama aides said the president would return to political travel Thursday with stops in Wisconsin, Nevada, and Colorado.