CHICAGO -- 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 percent for much of his first term.

And 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 under his stewardship the economy was beginning to recover. In every speech, he laid siege to his Republican rival, cautioning that Mitt Romney would return the United States to the same failed policies that plunged the economy into a downward spiral.

And he was aided by an experienced campaign operation that he called “the best ever” in his acceptance speech Wednesday morning. Operatives succeeded early in determining which states would make up the election map, and the fight was waged primarily in those states, strategists said.

Obama thanked them in person Wednesday, dropping by his campaign headquarters in Chicago before returning to the business of governing in Washington. He walked in to a standing ovation; staffers and volunteers climbed on top of desks to get a look at him, a source in the room said.

A survey of voters as they left polling places Tuesday showed six in 10 voters said the economy is the top issue facing the nation, 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 downtown challenges than Obama, according to preliminary results of an exit poll conducted for The Associated Press.

In the end, Romney, the former Massachusetts governor, 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.

“One thing they’ve done well is trash Mitt Romney,” said Whit Ayres, a Republican political consultant who co-founded a polling firm. “They’ve done a stellar job running an exceedingly personal campaign against Mitt Romney. It’s been challenging for Romney to overcome.”

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

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

“We wanted to chart multiple paths to victory, a Southern route, a Midwestern route, a Western route. I think it will bear out that it was a smart strategy to take those multiple routes to victory because you’re seeing these states tonight – many are very tight,” he said late Tuesday.

Democratic strategist Tad Devine said Romney made a “huge mistake” in letting Obama define the map and in waiting until the last minute to campaign in Pennsylvania and Minnesota. “Some of the places (Romney) wandered into in the final days, he should have been in at the front end,” he said.