With Hurricane Sandy sweeping the East Coast of the United States, causing widespread flooding and power outages, it is hard to predict what kind of role the dramatic weather might play in the tight presidential election seven days away.

Key swing states such as North Carolina, Virginia and Ohio have felt the strong impact of the hurricane.

Maryland Governor Martin O'Malley canceled early voting in the state on Monday. Early voting was also cancelled Monday in Washington, DC.

Virginia Governor Bob McDonnell said his state will extend early voting hours and restore power quickly to election facilities in the event of power outages.

A Washington Post poll released on Sunday revealed that US President Barack Obama lead Republican presidential candidate Mitt Romney 51 percent to 47 percent in Virginia, just outside the poll's margin of error.

Both candidates have canceled or changed their campaign plans for the coming days due to the hurricane.

Romney spent Monday afternoon campaigning in Iowa, but cancelled a Tuesday night event in Milford, New Hampshire, after the city was hit by the hurricane.

The Romney campaign has also stopped sending fundraising emails to places that are expected to be hit by the hurricane, including New Jersey, North Carolina, Pennsylvania, Virginia and Washington, DC.

Obama left the White House for Florida on Sunday evening after meeting Federal Emergency Management Agency officials to discuss preparations. He had planned to go ahead with campaign events in Florida on Monday, but by Monday morning, he decided to drop the event in Orlando at noon and return to the White House after realizing the severity of the storms.

He also canceled his campaign stops in Virginia on Monday and in Colorado on Tuesday.

Obama has rescheduled an event in Youngstown, Ohio, on Tuesday with former President Bill Clinton. Ohio is a key swing state that both candidates need to place well in the election.

Obama has events arranged through to Thursday in Ohio, Colorado and Nevada, but none of these might happen given the disaster relief work that would call for his attention.

As commander in chief, Obama is expected to greatly reduce his campaign time and focus on disaster relief. Most Americans still remember how the slow response by then President George W. Bush to Hurricane Katrina in New Orleans in 2005 overshadowed the remainder of his presidency.

While an incumbent president can easily attract criticism from people hit by the hurricane, it could also be a time for Obama to show his empathy and leadership.

In a White House briefing on Monday, Obama said he has spoken to all the governors in those states. "The federal government is working effectively with the state and local governments. ... My message to the governors as well as the mayors is anything they need, we'll be there," Obama said.

Asked about the hurricane's impact on the election, he said: "I am not worried at this point on the impact on the election. I'm worried about the impact on families and our first responders. The election will take care of itself next week."

It is believed that Romney will not try to exploit the hurricane to attack Obama. He suffered a backlash when he blamed Obama for the handling of the US consulate attack in Benghazi, Libya, soon after the incident.

Instead, the Romney campaign has announced plans to collect supplies for potential storm victims in Virginia.

With candidates changing their campaign plans in the last few days leading up to the election, there are also concerns that the storm might impact the election in other ways, such as causing damage to polling stations, preventing voters from seeing campaign ads, reducing TV coverage of the election and discouraging undecided voters to travel to polling stations.

With most federal offices in Washington closed on Monday, thousands of flights to the East Coast canceled, all public schools in New York, Washington and Boston closed and much of the public transit systems shut down or altered, no one seems to be sure what the real impact of Hurricane Sandy will be on the close presidential race.

It is expected that flooding and power outages in many parts of the East Coast will take days, if not weeks, to settle.

Opinion polls show the race to be essentially tied at the national level.

A Reuters/Ipsos tracking poll released on Sunday found Obama leading Romney among likely voters by 49 percent to 46 percent. Among registered voters, Obama held a wider lead of 51 percent to 39 percent.

chenweihua@chinadaily.com.cn