The president's laserlike focus on the battleground states allowed him to run up a 303-206 margin in the competition for the 270 electoral votes needed to win the White House, the count that mattered most. Remarkably, given the sour economy, he lost only two states that he captured in 2008, Indiana and North Carolina.
Florida, another Obama state four years ago, remained too close to call.
The election emerged as a choice between two very different visions of government — whether it occupies a major, front-row place in American lives or is in the background as a less-obtrusive facilitator for private enterprise and entrepreneurship.
The economy was rated the top issue by about 60 percent of voters surveyed as they left their polling places. But more said former President George W. Bush bore responsibility for current circumstances than Obama did after nearly four years in office.
That boded well for the president, who had worked to turn the election into a choice between his proposals and Romney's, rather than a simple referendum on the economy during his time in the White House.
Unemployment stood at 7.9 percent on Election Day, higher than when the president took office. And despite signs of progress, the economy is still struggling after the worst recession in history.
Obama captured Ohio, Wisconsin, Iowa, Virginia, New Hampshire, Colorado and Nevada, seven of the nine states where the rivals and their allies poured nearly $1 billion into dueling television commercials.
Romney won North Carolina among the battleground states.
Florida was too close to call, Obama leading narrowly in a state where there were still long lines of voters at some polling places long after the appointed closing time.
Romney, who grew wealthy in business and ran the 2002 Olympic Games in Salt Lake City before entering politics, spoke only briefly to supporters, some of whom wept.