David Jackson, USA TODAY
President John F. Kennedy said that "victory has a thousand fathers, but defeat is an orphan" - though President Obama and his aides cited a single reason for their re-election success.
Obama campaign officials said their get-out-the-vote organization - the people who make calls, knock on doors, micro-target potential voters and drive supporters to the polls - was more than three years in the making, building on their record-breaking effort in 2008.
"We had a good organization in '08," said Obama senior adviser David Plouffe. "This organization is light-years ahead of that."
Getting Obama loyalists into voting booths helped the president overcome anxiety over the economy and well-funded Republican challenger Mitt Romney on his way to a second term in the White House.
Watch: President Obama's victory speech
Story: Why Governor Mitt Romney lost
And immediately after it was over, Obama's campaign sent an e-mail to supporters to thank them for it. "I want you to know that this wasn't fate, and it wasn't an accident. You made this happen," said the message signed "Barack." "You organized yourselves block by block. You took ownership of this campaign five and ten dollars at a time."
Still, Kennedy had a point - many other factors sired Obama's victory.
They included one big policy decision with a big impact on a big state - the auto bailout in Ohio. The incumbent also appeared to benefit from nature's version of the October Surprise, Hurricane Sandy.
Then, of course, there's the candidate himself. Obama, enjoying the advantages of incumbency, remained a powerful speaker, with star power on the stump.
And historians also may cite the political influence of four very different individuals: George W. Bush, Bill Clinton, Osama bin Laden, and Romney himself.
Among the keys to Obama's victory:
Ohio and the auto bailout. Obama aides always believed that winning Ohio - as they did in 2008 - would seal re-election. They put a special effort into the Buckeye State by touting the government rescue of Chrysler and General Motors - a resonant issue in Ohio, where an estimated one in eight jobs depends on the auto industry.
Hurricane Sandy. The massive, deadly storm that slammed into the Northeast on Oct. 29 gave Obama a chance to exhibit presidential leadership in a very public way. New Jersey's prominent Republican Gov. Chris Christie - who had been the keynote speaker at the GOP convention in August - praised Obama's leadership and the federal response to the devastation the storm wrought upon his state. The storm also basically froze the race, forcing Romney to suspend his campaign at a time when some pollsters saw him gaining momentum.
Defining Romney. For many voters, the Obama campaign successfully portrayed Romney as a plutocrat businessman out of touch with the concerns of middle-class Americans. Romney himself also helped that effort. A key event: The surfacing of a video from a private Romney fundraiser, in which the Republican candidate was heard dismissing "47%" of Americans who either don't pay taxes or live off government assistance.
Former presidents. George W. Bush and Bill Clinton. Obama often talked about the "mess" he inherited from his Republican predecessor, from a near-collapse of the economy to long wars in Iraq and Afghanistan. Enough voters apparently agreed with the incumbent's assessment that things are getting better, while Romney's policies mirrored those of the Bush years.
Clinton, a rival after Obama defeated Hillary Rodham Clinton in the 2008 Democratic primaries, came to the incumbent's rescue throughout this election season. His speech to the Democratic convention - defending Obama's economic record, denigrating Romney's economic plans, and reviving memories of the economic boom of the 1990s - may have been the highlight of the Democrats' week in Charlotte.
Osama bin Laden. The daring 2010 raid that killed the al-Qaeda founder bolstered Obama's national security credentials, often a weak spot for Democratic candidates. The president's record of ending the war in Iraq and winding down of the war in Afghanistan also proved popular with many voters. The campaign's summary message was "Osama bin Laden is dead, and General Motors is alive."
In the end, however, Obama and his aides kept returning to organization as the key to their re-election bid. The president made this case constantly on the stump.
On Election Day itself, during a morning visit to a campaign office, Obama said: "We feel confident we've got the voters to win ... it's going to depend ultimately on whether those voters turn out."
Enough of them did to give Obama a new lease on White House life.