Obama was first to get off the campaign trail, rushing out of battleground Florida ahead of a planned rally to monitor the storm in Washington and calling off a trip to Wisconsin Tuesday. Romney followed suit shortly after the president arrived back at the White House by canceling all events he and running mate Paul Ryan had scheduled for Monday night and Tuesday.
"Sandy is another devastating hurricane by all accounts, and a lot of people are going to be facing some real tough times as a result of Sandy's fury," Romney said at a campaign stop in Ohio. He also planned to stop in swing state Iowa before standing down as the storm was predicted to make landfall Monday night.
Obama was trying to balance the need to show command in crisis while in the final throes of a tough re-election campaign. Upon arrival at the White House, he planned to convene a video conference in the Situation Room with administration officials monitoring the storm's path and running the response, then speak to reporters.
The president met with federal emergency officials Sunday before flying to Florida that night ahead of a rally scheduled for Monday. 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. Obama made a bumpy flight back to Washington and landed in a driving rain that forced him to take his motorcade, rather than his helicopter, back to the South Lawn upon arrival.
White House spokesman Jay Carney said they changed plans because the storm picked up speed and intensity overnight, making it necessary for the president to leave earlier if he hoped to get back to Washington.
"The president's priority right now is the safety and security of Americans who are in the path of the storm," Carney said. "It's essential in his view that he be in Washington ... to oversee that effort and to be updated on it."
Obama's plans to campaign Wednesday in Ohio were still on, though campaign officials said they were evaluating travel plans on an almost hourly basis.
Most of the White House news media representatives who accompanied Obama to Florida were left there after the pilots of separate, charter flights determined it was unsafe to follow Air Force One back to Washington.
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.
While the impact of the storm had yet to be seen, at the very least it was a distraction as both sides were looking to make their final appeals and millions of ballots were already being cast in early voting. It threatened to dilute Romney's efforts to close the deal with voters while giving Obama a platform to show leadership in the time of crisis. And power outages could end up cutting off their message in television ads and automatic phone calls in the eastern swing states.
Obama advisers said they said they were confident in their ground game even if Obama has to curtail his campaign appearances.
"We're obviously going to lose a bunch of campaign time," senior campaign adviser David Axelrod told reporters in a conference call. "We'll try to make it up on the back end."
Republicans concede that the storm essentially pushes a pause button on the momentum Romney had been building in key states across the country, but argue that it's not necessarily a bad thing. They insist they are in strong positions in battlegrounds like Ohio, Florida, Colorado and Iowa, but acknowledge that Virginia could be a problem. Romney was forced to cancel three rallies planned for the state on Sunday and it's unclear when he'll be able to return.
Romney's campaign is considering a plan to send the candidate to New Jersey later this week, where he could meet with victims and gauge damage with political ally Gov. Chris Christie. The move would follow the path Romney took in the wake of Hurricane Irene following the Republican National Convention, when he toured storm damage in Louisiana with Gov. Bobby Jindal, also a supporter.
Former President Bill Clinton still planned to appear before voters at the Orlando rally in Obama's absence. 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.
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.
Clinton planned to campaign in the state Tuesday with likely stops on college campuses, before continuing on a tireless swing to help fill Obama's void this week to Iowa, Colorado, Ohio, Virginia, New Hampshire and Wisconsin.
Both campaigns used social media to urge supporters to donate to the Red Cross and said they would stop sending fundraising emails on Monday to people living in areas in the storm's path.
Romney staffers in North Carolina, New Hampshire, Pennsylvania and Virginia were collecting storm-relief supplies at campaign offices to be delivered via one of Romney's campaign buses. In an email, Romney encouraged supporters in the storm's path to help neighbors get ready.
"For safety's sake, as you and your family prepare for the storm, please be sure to bring any yard signs inside," the email read. "In high winds they can be dangerous, and cause damage to homes and property."