The superstorm ravaging the US East Coast laid waste to the campaign strategies of President Barack Obama and Republican challenger Mitt Romney with just a week remaining in their intensely close race for the White House.
Mr Obama cancelled a third straight day of campaigning, calling off appearances scheduled for Wednesday in Ohio, the most important of the battleground states. He will remain in Washington to monitor the storm and the federal response.
He had already cancelled events to manage the vast emergency that hit the heavily populated region between Washington and Boston and stretched toward Chicago and the Midwest. Vice President Joe Biden joined him in shunning campaign events.
Mr Romney and running mate Paul Ryan initially announced they were cancelling events out of sensitivity for the millions of American's in Sandy's path.
But Mr Romney went forward with a planned event in Ohio, though it focused on storm relief. Mr Ryan cancelled three Colorado appearances.
Both candidates sought to avoid the appearance of putting politics above Americans' more immediate worries over flooding, power cuts, economic calamity and personal safety.
With the outcome of the November 6 election likely to be decided by the thinnest of margins, the storm will dominate news coverage and distract many millions of voters in the critical few days left for the candidates to win over those who remain undecided.
"When the nation's largest city and even its capital are endangered, when so many people are in peril and face deprivation, it's hard to get back to arguing over taxes," said historian and presidential biographer Douglas Brinkley.
Mr Obama declared a "major disaster" in New York City and parts of New Jersey after being updated throughout the night.
He kept in frequent touch with leaders of affected states, prompting the highly partisan Republican governor of New Jersey, Chris Christie, to offer rare high praise.