Virginia

Virginia is vital to almost every one of Mr. Romney’s paths to the White House if he does not win Ohio, which explains why he has spent so much time visiting the state, including what were to be three rallies on Sunday before they were canceled because of Hurricane Sandy.

Mr. Obama was the first Democrat to win the state since 1964. The tide he rode among black voters in places like Hampton, on the coast, is likely to roll again. And the northern part of the state, in the Washington area, is still considered Obama country.

Mr. Romney has focused much of his effort in areas like those around Norfolk, heavily populated with military personnel, where he asserts that Mr. Obama has allowed the Navy to wither, and in coal-mining country in the south, where he portrays Mr. Obama as hostile to the industry and quick to impose costly regulations on business.

A run of polls in the late summer showed Mr. Obama to be on his way to establishing a real advantage, but in recent weeks the race has fallen into an effective tie. Mr. Romney’s improving standing among undecided women after the debates — which he stoked with an advertisement that sought to soften his stance against abortion — made Mr. Obama’s aides especially nervous.

The president’s campaign has been buoyed by recent indications that those wavering women in the north seem to be returning to his column, especially as Democrats remind them of the anti-abortion measures that state Republicans pursued this year.