The long campaign's cost soared into the billions, much of it spent on negative ads, some harshly so.
In a months-long general election ad war that cost nearly $1 billion, Romney and Republican groups spent more than $550 million and Obama and his allies $381 million, according to organizations that track advertising.
According to the exit poll, 53 percent of voters said Obama was more in touch with people like them, compared to 43 percent for Romney.
About 60 percent said taxes should be increased, taking sides on an issue that divided the president and Romney. Obama wants to let taxes rise on upper incomes, while Romney does not.
Other than the battlegrounds, big states were virtually ignored in the final months of the campaign. Romney wrote off New York, Illinois and California, while Obama made no attempt to carry Texas, much of the South or the Rocky Mountain region other than Colorado.
There were 33 Senate seats on the ballot, 23 of them defended by Democrats and the rest by Republicans.
Democratic Rep. Chris Murphy, a Democrat, won a Connecticut seat long held by Sen. Joe Lieberman, retiring after a career that included a vice presidential spot on Al Gore's ticket in 2000. It was Republican Linda McMahon's second defeat in two tries, at a personal cost of $92 million.
The GOP needed a gain of three for a majority if Romney won, and four if Obama was re-elected. Neither Majority Leader Harry Reid of Nevada nor GOP leader Mitch McConnell of Kentucky was on the ballot, but each had high stakes in the outcome.
All 435 House seats were on the ballot, including five where one lawmaker ran against another as a result of once-a-decade redistricting to take population shifts into account. Democrats needed to pick up 25 seats to gain the majority they lost two years ago.
House Speaker Boehner, R-Ohio, raised millions to finance get-out-the-vote operations in states without a robust presidential campaign, New York, Illinois and California among them. His goal was to minimize any losses, or possibly even gain ground, no matter Romney's fate. House Democratic leader Rep. Nancy Pelosi of California campaigned aggressively, as well, and faced an uncertain political future after her party failed to win control.
Democrats toppled conservative tea party freshman Reps. Joe Walsh and Bobby Schilling in Illinois, as well as another freshman, Robert Dold and seven-term veteran Judy Biggert, a social moderate.
Other GOP casualties included Rep. David Rivera of Florida, who was hurt by investigations into his past campaign financing; Ann Marie Buerkle of New York, who lost to the Democrat she defeated in 2010, Dan Maffei, and New Hampshire Republican Charlie Bass, ousted by Ann Kuster, the Democrat he defeated narrowly two years ago.
Republicans turned Rep. Kathy Hochul out of office in New York, as well as Larry Kissel in North Carolina, Mark Critz in Pennsylvania and Ben Chandler in Kentucky.
In gubernatorial races, Republicans picked up North Carolina, where Pat McCrory won easily. The incumbent, Democratic Gov. Bev Purdue, did not seek re-election.
In a campaign that traversed contested Republican primaries last winter and spring, a pair of political conventions this summer and three presidential debates, Obama, Romney, Biden and Ryan spoke at hundreds of rallies, were serenaded by Bruce Springstein and Meat Loaf and washed down hamburgers, pizza, barbecue and burrito bowls.
Obama was elected the first black president in 2008, and four years later, Romney became the first Mormon to appear on a general election ballot. Yet one man's race and the other's religion were never major factors in this year's campaign for the White House, a race dominated from the outset by the economy.
Over and over, Obama said that during his term the nation had begun to recover from the worst recession since the Great Depression. While he conceded progress had been slow, he accused Romney of offering recycled Republican policies that have helped the wealthy and harmed the middle class in the past and would do so again.
Romney countered that a second Obama term could mean a repeat recession in a country where economic growth has been weak and unemployment is worse now than when the president was inaugurated. A wealthy former businessman, he claimed the knowledge and the skills to put in place policies that would make the economy healthy again.
In a race where the two men disagreed often, one of the principal fault lines was over taxes. Obama campaigned for the renewal of income tax cuts set to expire on Dec. 31 at all income levels except above $200,000 for individuals and $250,000 for couples.
Romney said no one's taxes should go up in uncertain economic times. In addition, he proposed a 20 percent cut across the board in income tax rates but said he would end or curtail a variety of tax breaks to make sure federal deficits didn't rise.
The differences over taxes, the economy, Medicare, abortion and more were expressed in intensely negative advertising.
Obama launched first, shortly after Romney dispatched his Republican foes in his quest for the party nomination.
One memorable commercial showed Romney singing an off-key rendition of "America The Beautiful." Pictures and signs scrolled by saying that his companies had shipped jobs to Mexico and China, that Massachusetts state jobs had gone to India while he was governor and that he has personal investments in Switzerland, Bermuda and the Cayman Islands.
Romney spent less on advertising than Obama. A collection of outside groups made up the difference, some of them operating under rules that allowed donors to remain anonymous. Most of the ads were of the attack variety. But the Republican National Committee relied on one that had a far softer touch, and seemed aimed at voters who had been drawn to the excitement caused by Obama's first campaign. It referred to a growing national debt and unemployment, then said, "He tried. You tried. It's OK to make a change."
More than 30 million voters cast early ballots in nearly three dozen states, a reflection of the growing appeal of getting a jump on the traditional Election Day.