Obama and his team attacked Romney's politics and his background as a venture capitalist, saying he would back policies favoring the wealthy over the middle class and exacerbate the already widening income and opportunity disparity in the country.

The president portrayed the race as competing visions for the future and built on his central theme of restoring the promise of the American dream of equal opportunity for all.

In particular, Obama repeatedly noted he backed a taxpayer bailout that helped restore General Motors and Chrysler while Romney opposed it. The issue resonated in auto industry states like Michigan and Ohio, both of which ended up providing crucial electoral votes for Obama.

Aside from the policy differences, the election amounted to a campaign chess match targeting specific states and demographic groups as part of a plan to create a path to electoral success.

Re-election offered Obama, 51, the chance to secure a two-term legacy and seek further reforms he promised in his historic campaign of 2008 but was unable to deliver in the first four years. In particular, he has made comprehensive immigration reform a top target, as well as a deficit reduction plan that ends tax breaks for income over $250,000.

However, the wave of optimism that carried to him to victory four years ago seemed muted during the campaign this time, with former supporters angered by the failure to achieve the kind of change in Washington they believed Obama had promised but failed to deliver.

For Romney, who sought to become the nation's first Mormon president, the election concluded a six-year quest for the White House.

Romney also failed in his first bid for the Republican nomination in 2008, then spent the next two years preparing for a second run that began in 2011 with the GOP primary campaign.

The 65-year-old was trying to win the office that his father -- former Michigan Gov. George Romney -- also sought but fell well short of winning in 1968.