NASHUA, N.H. -- Racing to get their last-minute messages across before campaigning is overshadowed by Hurricane Sandy, President Barack Obama and Republican challenger Mitt Romney Saturday made impassioned pitches to voters in the swing states of Florida and New Hampshire.

As the potentially devastating storm began barreling up the Eastern Seaboard, Romney spent the day in Florida, where early voting began Saturday. Obama rallied supporters in New Hampshire on the last day people can register to vote before Election Day.

The storm’s political impact was already being felt. Romney canceled scheduled Sunday appearances in Virginia to head for Ohio instead. Obama went ahead with plans to campaign on Monday but canceled plans to campaign on Tuesday so he could return to the White House to monitor events.

“The President will continue to receive regular briefings on these efforts, and has made clear that he expects his team to continue to lean forward as Hurricane Sandy approaches,” White House Press Secretary Jay Carney said Saturday evening in a statement that used the campaign theme, forward, with the comments on governing.

At the outset of such catastrophes, presidents have an opportunity to gain support, since they can show they’re effectively managing a crisis. That can backfire, too, as President George W. Bush learned in the bungled aftermath of Hurricane Katrina in 2005.

In Florida, Romney told supporters that they should keep residents along the Eastern Seaboard in "your minds, your hearts.” “Yu know how tough these hurricanes can be,’’ he said.

If the storm intensifies, it’s likely to get tougher for Romney and Obama to get the attention of voters in these final, crucial days before the Nov. 6 election. It could also hurt their get-out-the-vote effort in early voting states. Polls show Obama and Romney locked in a statistical tie nationally and in the 11 swing states likely to decide the presidency.

Florida has 29 electoral votes, while New Hampshire has four. If the race remains tight, as expected, even those four votes could be important, and Obama and Romney are neck and neck there.

“These four electoral votes right here could make the difference,” Obama told 60 supporters at his first stop Saturday at a Teamsters’ hall in Manchester.

Next it was on to the Elm Street Middle School in Nashua, where Obama warned that Romney has “an entirely different view of what this country’s about.” An audience estimated ay 8,500 booed, and Obama smiled and implored them, “Don’t boo, don’t.”

He joked about Romney’s 2003-2007 stint as governor of Massachusetts, a state just minutes away from the campaign site. “He raised fees to get a birth certificate,” Obama joked, “which would have been expensive for me.” Obama was born in Hawaii, and released his long-form birth certificate last year, but some critics have questioned his place of birth.

He also continued to make a special appeal to women, insisting “We don’t need a whole bunch of politicians in Washington, most of whom are male, making health care decisions for women.”

Romney made his case in Florida, which narrowly voted for Obama in 2008. Polls this week show Romney inching ahead there as the economic downturn has hit the state particularly hard, leaving a slew of home foreclosures and an unemployment rate higher than the national average.