4BC News:Barack Obama wasn't supposed to win re-election.

The hope was gone, critics said, evaporated by endless partisan gridlock in Washington and a jobless rate that hovered above 8 per cent for much of his first term.

Yet a relentlessly focused campaign, a flicker of economic good news - witnessed in rebounding consumer confidence - and a prolonged assault on his opponent persuaded voters to give the Democrat who made history in his 2008 election another four years in office.

In campaign stops across battleground states, Obama pressed for patience, arguing that he'd prevented an economic collapse and that the economy was beginning to recover.

In every speech, he laid siege to his Republican rival, cautioning that Mitt Romney would return the US to the same failed policies that plunged the economy into a downward spiral.

A survey of voters as they left polling places showed six in 10 voters believed the economy was the top issue, with unemployment and rising prices hitting voters hard.

But about half of voters said former President George W. Bush was more responsible for the economic challenges than Obama, according to preliminary results of an exit poll conducted for The Associated Press.

In the end, Romney failed to convince enough voters he was on their side - a storyline the Obama campaign pursued with a single-minded focus before Romney had even clinched his party's nomination.

The portrait of Romney that emerged was of an elite executive who led a private equity firm that drove jobs overseas and cut employment in the United States.

"They've done a stellar job running an exceedingly personal campaign against Mitt Romney," said Whit Ayres, a Republican political consultant. "It's been challenging for Romney to overcome."

Obama's campaign also succeeded in determining early which states would make up the election map. Those included the battleground states of Florida, Ohio, Virginia, Colorado and Nevada.

Obama campaign spokesman Ben LaBolt said the president had succeeded in rebuilding a similar coalition to the one he had in 2008 after focusing on several key states.

"We wanted to chart multiple paths to victory, a Southern route, a Midwestern route, a Western route," he said.

Democratic strategist Tad Devine said Romney had made a "huge mistake" in letting Obama define the map and in waiting until the last minute to campaign in Pennsylvania and Minnesota.

Democrats say Obama was able, despite the sluggish economy, to point to achievements.

He trumpeted success at preventing the economy from hitting bottom with a stimulus plan that ploughed government dollars into hiring.

He achieved health care legislation, enacted a firewall to prevent a relapse of the Wall Street fiasco, backed a federal bailout to save auto industry jobs, ended the war in Iraq and oversaw the raid that ended in the death of Osama bin Laden.

"Osama bin Laden is dead and General Motors is alive," Vice President Joe Biden suggested as an Obama campaign bumper sticker. "That about sums it up, man."

At the close of the election, Obama was boosted by a crisis beyond any candidate's control.

As the massive storm Sandy barrelled up the East Coast, Obama suspended his campaign appearances to tend to the emergency response, projecting an air of confidence and compassion and avoiding the criticism that plagued former President George W. Bush in the wake of Hurricane Katrina.

As Obama toured the hard-hit New Jersey coast with the state's Republican governor Chris Christie he drew effusive praise from the rising Republican star and previously sharp-tongued critic.

Christie just a week earlier had assailed Obama's leadership skills.

With polls over the summer suggesting white voters were leaning Republican by a sizeable margin, Obama's campaign dispatched surrogates like Biden to stem the loss by courting the white, working-class voters Obama had a harder time reaching.

The campaign also relied heavily on former President Bill Clinton to reach that voting bloc.

Obama gave Clinton a starring role at his convention where Clinton delivered a dazzlingly powerful endorsement for a second Obama term.

In addition, Obama benefitted from the fact he'd done it before. After the 2008 election, the campaign never left. Through Organising for America, an arm of the Democratic National Committee, Obama maintained ties in swing states, continuing to hold events and build support.

By contrast, Romney clinched his party's nomination this past spring after a long primary battle, leaving him far less time to build up an organisation.

Although powerful outside groups backing Romney raised more money, Obama's campaign held its own, according to the Centre for Responsive Politics.

Obama's campaign still managed to raised $630 million as of mid-October, significantly more than Romney's $390 million.

Obama returned late Monday night to Iowa, the battleground state he credits with starting it all.

His voice hoarse, his eyes wet from emotion or the cold, he asked the crowd to keep the faith, acknowledging, "sometimes it's been hard. Sometimes it's been frustrating."

But, he added: "I'm not ready to give up on the fight. I've got a lot more fight left in me."

Four more years. twitter.com/BarackObama/st…

— Barack Obama (@BarackObama) November 7, 2012

BREAKING: Romney says nation at a critical point, urges Americans not to engage in partisan bickering. #Election2012

— The Associated Press (@AP) November 7, 2012

CNN estimates are updated in real time on a rather breathtaking graphic template: The Empire State.. twitter.com/carr2n/status/…

— david carr (@carr2n) November 7, 2012

twitter.com/LanaDopeRey/st…

— Get Sleazy (@LanaDopeRey) November 7, 2012

This happened because of you. Thank you.

— Barack Obama (@BarackObama) November 7, 2012

Romney asks his supporters to pray for Obama, and the nation.

— NowThis News (@nowthisnews) November 7, 2012

"We have legal marijuana - not just medicinal marijuana - legal marijuana in Washington and Colorado." - @cenkuygur #current2012

— Cenk Uygur (@cenkuygur) November 7, 2012

As Fox News decision desk defies Karl Rove's theory that Ohio is still up for grabs, crowd at Romney HQ isn't sure how to react.

— Bill Weir (@BillWeirABC) November 7, 2012

We can't let this happen. We should march on Washington and stop this travesty. Our nation is totally divided!

— Donald J. Trump (@realDonaldTrump) November 7, 2012

“@barackobama: @rickygervais This happened because of you. Thank you."Haha. Cheers. My pleasure.

— Ricky Gervais (@rickygervais) November 7, 2012

Big bird voting is the best picture today. twitter.com/samir/status/2…

— Samir Mezrahi (@samir) November 6, 2012

This election is a total sham and a travesty. We are not a democracy!

— Donald J. Trump (@realDonaldTrump) November 7, 2012

We're all in this together. That's how we campaigned, and that's who we are. Thank you. -bo

— Barack Obama (@BarackObama) November 7, 2012

Big groups of young people literally running down Penn Ave to get to White House.

— Amanda Terkel (@aterkel) November 7, 2012

Big Bird lives to fight another day.

— Andrew Kaczynski (@BuzzFeedAndrew) November 7, 2012

My fellow Republicans: We can now stop pretending that we like Mitt Romney. Hallelujah.

— Gov. Chris Christie (@GovChristieNJ) November 7, 2012

Wow. Bill O'Reilly just said this on FOX: "It's Not a Traditional America Anymore... The White Establishment Is Now a Minority..."

— Michael Moore (@MMFlint) November 7, 2012

Tea Party has now cost the Republicans 5 senate seats. My next donation is going to them.

— Bill Maher (@billmaher) November 7, 2012

Romney traded up the state of Ohio for the state of denial *BA-DUM-KSSH*

— Matthew Inman (@Oatmeal) November 7, 2012

Mitt Romney: You're FIRED. #letsmakedonaldshthimself

— Téa Smith (@tealou) November 7, 2012

Last thought: GOP lost two senate seats tonight directly as a result of rape comments. Women's votes and voices matter. #feminism

— Louise Mensch (@LouiseMensch) November 7, 2012