Barack Obama has received the endorsement of New York City's popular mayor as the president and Republican challenger Mitt Romney opened a final campaign blitz in the last days of their race for the White House.
The pair were streaking between campaign stops in the all-important swing states ahead of Tuesday's vote after a three-day hiatus for Mr Obama to manage the crisis surrounding superstorm Sandy. Mr Romney toned down criticism of the White House incumbent during those days for fear of appearing to seek political advantage while Americans were battered by the historic natural disaster.
Thursday's endorsement of Mr Obama by New York City's Michael Bloomberg, the popular and politically independent third-term mayor of America's largest city, was a major boost for the president, who is spending the campaign's final days trying to win over independent voters who will be critical in determining who wins the November 6 vote.
Both candidates had eagerly sought the backing of Mr Bloomberg, who did not endorse a presidential candidate in 2008.
Mr Bloomberg, whose city was hard hit by the monster storm, said Sandy had made the stakes of the election even clearer. The billionaire businessman and former Republican said the climate is changing and that Mr Obama has taken major steps in the right direction.
Of the two White House rivals, Mr Bloomberg wrote in his endorsement that was posted on the internet: "One sees climate change as an urgent problem that threatens our planet; one does not. I want our president to place scientific evidence and risk management above electoral politics."
In another possible boost for Mr Obama, government and private sources were reporting a series of encouraging numbers about the economy, the consistently dominant issue in the race.
Reports on home prices, worker productivity, car sales, construction spending, manufacturing and retail sales suggested the recovery was picking up pace, and a measurement of consumer confidence rose to its highest level since February 2008.
None of the day's measurements packed the political significance of the campaign's final report on unemployment, due out on Friday. Joblessness was measured at 7.8% in September, falling below 8% for the first time since Mr Obama took office.
Both Mr Obama and Mr Romney were pressing intense closing arguments in their astonishingly close race as officials across the country reported that more than 20 million Americans had already cast ballots in early voting states. The president moved quickly across three battleground states once he returned to campaigning on Thursday while his challenger made three stops in critical Virginia.