Republican nominee Mitt Romney was campaigning in the Midwest Monday out of the storm's path, but called off events scheduled in Virginia Sunday and New Hampshire Tuesday.
Obama, mindful of his need to show command in crisis while in the final throes of a tough re-election campaign, met with federal emergency officials Sunday before flying to Florida that night ahead of a rally scheduled for Monday at noon. But the intensifying storm heading to the East Coast took priority, with the president signing emergency declarations for New England states in the middle of the night from his Orlando hotel room.
By dawn the White House decided to call off the politicking. Air Force One lifted off for Washington around 8:30 a.m. EDT.
"Due to deteriorating weather conditions in the Washington area, the president will not attend today's campaign event in Orlando," spokesman Jay Carney said in a written statement. "The president will return to the White House to monitor the preparations for and early response to Hurricane Sandy."
Obama's aides considered moving the Orlando event even earlier Monday morning but were told that would put Air Force One back too late to land safely. Nearly all commercial flights had already been canceled in the Washington area as heavy rains soaked the capital ahead of Sandy's expected landfall Monday night.
With eight days before Election Day, neither campaign could afford to fully shut down its political activity in a race that remains tight. Four critical election states are affected by the storm — North Carolina, Virginia, Ohio and New Hampshire — but there was still unthreatened ground to cover across the rest of the country.
Romney was scheduled Monday to campaign in the perennial battlegrounds of Ohio and Iowa. He also was visiting Wisconsin, trying to force Obama to play defense in a state where the president has been leading in the polls despite the addition of native son Paul Ryan on the GOP ticket.
"I know that right now some people in the country are a little nervous about a storm about to hit the coast, and our thoughts and prayers are with people who will find themselves in harm's way," Romney told supporters in Ohio on Sunday.
Former President Bill Clinton still planned to appear before voters at the Orlando rally. Later Clinton and Vice President Joe Biden were appearing together in Youngstown, Ohio. Biden was originally supposed to campaign in New Hampshire Monday, but diverted to Ohio to replace Obama after the president canceled his appearance to stick to Washington.
But the abrupt cancellation meant Obama's trip to Florida was essentially a waste. The campaign bumped up the rally by two hours and rescheduled his flight to Orlando from Monday morning to Sunday night to get ahead of the storm.
The president made an unannounced stop at a campaign office Sunday night, where he told supporters the storm meant he wouldn't be able to campaign as much over the next few days.
"You guys need to carry the ball," he told the volunteers.
Polls suggest Obama has an advantage in reaching the required 270 Electoral College votes. But Romney's campaign is projecting momentum and considering trying to expand the playing field beyond the nine states that have garnered the bulk of the candidates' attention.
A senior Republican official, speaking on the condition of anonymity to disclose private deliberations, said Romney's team was discussing sending the GOP nominee, Ryan or both to traditionally left-leaning Minnesota during the campaign's final week.
Obama was briefed Sunday on the government's response at the headquarters of the Federal Emergency Management Agency and spoke by phone to affected governors and mayors.
"Anything they need, we will be there," Obama said. "And we are going to cut through red tape. We are not going to get bogged down with a lot of rules. We want to make sure that we are anticipating and leaning forward."
Obama has declared emergencies in Massachusetts, Connecticut, Rhode Island, New York, New Jersey, Pennsylvania and the District of Columbia, authorizing federal aid to supplement state and local response efforts.
During the GOP primaries, Romney suggested the responsibility of responding to natural disasters should be stripped from FEMA and delegated to the states or private businesses.
"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. And if you can go even further, and send it back to the private sector, that's even better," Romney said during a Republican debate broadcast on CNN.
Earlier this year his running mate Ryan, the chairman of the House budget committee, tried to eliminate $10 billion a year in federal disaster aid. Under Ryan's failed proposal, when emergencies arise, Congress would pay for the disaster costs by cutting the federal budget elsewhere.
The president's campaign said it was using its presence on social media to urge supporters to donate to the Red Cross for storm relief efforts. And the campaign said it would stop sending fundraising emails on Monday to people living in areas in the storm's path.
Romney staffers across Virginia plan to collect supplies to deliver to local storm-relief centers after the hurricane hits. And one of Romney's campaign buses was to be used for relief efforts throughout the East Coast, the Republican National Committee said.
The storm was hitting as millions of Americans were already voting. Early voting has been a particular focus for Obama's campaign, which is banking on its massive get-out-the-vote operation to build up advantages ahead of Election Day.
Obama advisers said they didn't expect earlier voting to be significantly affected in any of the competitive states in the storm's path.
A small percentage of voters cast their ballots early in New Hampshire and Virginia. Obama's campaign was encouraging voters in Virginia, however, to take advantage of the state's decision to ease early voting restrictions because of the storm.
But early voting is robust in Ohio and North Carolina. Obama advisers said they were confident they had built up solid totals in the states before the storm that would serve as firewalls if the storm does keep other supporters from casting their votes.
Pickler reported from Washington. Associated Press reporters Steve Peoples in Mansfield, Ohio, and Ken Thomas in Washington contributed to this report.