WASHINGTON (AP) — President Barack Obama rolled to re-election Tuesday night, vanquishing former Massachusetts Gov. Mitt Romney and winning four more years in office despite a weak economy that plagued his first term and put a crimp in the middle class dreams of millions.

“This happened because of you. Thank you” Obama tweeted to supporters as he celebrated four more years in the White House.

Romney telephoned the president, then spoke to disappointed supporters in Boston.

After the costliest — and arguably the nastiest — campaign in history, divided government seemed alive and well.

Obama supporters gathered at his headquarters in Chicago, as well as in New York’s Times Square, at Faneuil Hall in Boston and near the White House in

Washington, drivers joyfully honking as they passed by.

With votes counted in 75 percent of the nation’s precincts, Obama held a narrow advantage in the popular vote, leading by about 25,000 out of more than 99 million cast.

But the president’s laser-like focus on the battleground states allowed him to run up a 303-203 margin in the competition for electoral votes, where the White House is won or lost. It took 270 to win.

Obama captured Ohio, Wisconsin, Iowa, New Hampshire, Colorado and Nevada, seven of the nine states where the rivals and their allies poured nearly $1 billion into dueling television commercials.

Florida remained too close to call, a state where there were long lines of voters kept the polls open in some areas well past the appointed poll close time.

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 bode well for the president, who had worked to turn the election into a choice between his proposals and Romney’s, rather than the simple referendum on the economy during his time in the White House.

Unemployment stood at 7.9 percent on election day, higher than when he took office. And despite signs of progress, the economy is still struggling after the worst recession in history.

There was no doubt about what drove voters to one candidate or the other.

Polls were still open in much of the country as the two rivals began claiming the spoils of a brawl of an election in a year in which the struggling economy put a crimp in the middle class dreams of millions.

The president was in Chicago as he awaited the voters’ verdict on his four years in office. He told reporters he had a concession speech as well as victory remarks prepared. He congratulated Romney on a spirited campaign. “I know his supporters are just as engaged, just as enthusiastic and working just as hard today” as Obama’s own, he added.

Like Obama, Vice President Joe Biden was in Chicago as he waited to find out if he was in line for a second term.

The long campaign’s cost soared into the billions, much of it spent on negative ads, some harshly so.

In the presidential race, an estimated one million commercials aired in nine battleground states where the rival camps agreed the election was most likely to be settled — Ohio, New Hampshire, Virginia, Florida, North Carolina, Wisconsin, Iowa, Colorado and Nevada.

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.

In Virginia, the polls had been closed for several minutes when Obama’s campaign texted a call for volunteers “to make sure everyone who’s still in line gets to vote.”

In Florida, there were long lines at the hour set for polls to close. Under state law, everyone waiting was entitled to cast a ballot.

According to the exit poll, 53 percent of voters said Obama is 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.

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 has begun to recover from the worst recession since the Great Depression. While he conceded progress has 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.

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.

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.

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.

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.