WASHINGTON — Eleven states are likely to decide whether President Obama or Republican Mitt Romney will be elected president Tuesday.

The winner needs to cobble together 270 electoral votes. Estimates by the website RealClearPolitics.com say that Obama can count on 201 and Romney 191 in the three-fourths of the nation where they look solid.

That leaves the battlegrounds. Spread across America, the swing states often share several characteristics: recent population increases, meaning lots of new voters; growing numbers of Latino voters; diverse populations that mirror the nation’s demographic makeup, and economies that are recovering slowly.

All the polls agree: It’s too close to call.

FLORIDA (29 electoral votes)

The latest surveys show a tight race. Lines for early voting, which ended Saturday, remained long during the week. And there could be as many as 2 million absentee ballots to count.

As of Thursday morning, Democrats held a 59,000-ballot advantage over Republicans in total pre-Election Day votes cast. But Republicans pointed out that, compared to 2008, Democrats aren’t in the position to rack up a major early-vote lead.

Part of the reason is that the Republican-led Legislature last year cut early voting days in the state to eight, down from 14 in 2008. In all, Democrats edged Republicans by 133,000 early-vote ballots over the last five days, but Republicans extended their absentee-vote lead to more than 74,000.

More than 3 million ballots have been cast out of a total of 12 million registered voters, 75 percent of whom are expected to vote. That means about a third of the ballots could already be in.

The race in Florida clearly appears to come down to which campaign can get its base of voters to the polls.

— Marc Caputo, The Miami Herald

NEW HAMPSHIRE (4 electoral votes)

New Hampshire is the smallest of the battleground states, but it’s almost evenly divided among the parties, so it could be a critical stepping stone on the path to 270.

Obama won the state soundly in 2008, though recent polls show him with an increasingly slim lead. Romney, who has a home in the state, governed neighboring Massachusetts and decisively won the New Hampshire primary in January, is hoping for a home state advantage. He plans a Monday night rally in Manchester.

Obama isn’t ceding ground. He and former President Clinton were scheduled to campaign in Concord on Saturday. Clinton remains a state favorite since he won New Hampshire in 1992, ending years of Republican dominance. In 2000, Al Gore lost the state by just 7,000 votes.

The state’s competitive nature is mirrored by its two U.S. senators: Democrat Jeanne Shaheen, elected in 2008, is campaigning for Obama; Republican Kelly Ayotte, elected in 2010, is campaigning for Romney.

— Lesley Clark, Washington Bureau

VIRGINIA (13 electoral votes)

Virginia’s recent and dramatic demographic transformation has shifted its electorate from reliably Republican to divided. Thousands of new residents, many of them diverse, more youthful and more educated, have crowded the sprawling suburbs outside the nation’s capital, turning the state into a toss-up.

“There’s just more independents in northern Virginia and frankly around the state,” said Virginia Gov. Bob McDonnell, a Republican.

Obama became the first Democratic presidential candidate to carry the state in more than four decades in 2008. But this year, surveys give Virginia the distinction of being the closest battleground state in the nation, according to RealClearPolitics.com.

“It used to be one of the most reliably Republican states,” said Mark Rozell, a professor at George Mason University. “It was assumed to be an automatic Republican win.”

— Anita Kumar, Washington Bureau

PENNSYLVANIA (20 electoral votes)

After being largely ignored through the general election season, is the recent attention given the Keystone State by Romney merely a tactic to force Obama to devote time and resources at the last minute to a state where he once held a commanding lead?

Pennsylvania Gov. Tom Corbett is a Republican, and the legislature is under Republican control. But the Republican Party’s recent presidential candidates have had little success. They draw support in the Lehigh Valley and Philadelphia’s Main Line suburbs, only to lose to Democratic candidates who rack up votes in urban Philadelphia and Pittsburgh.

Romney’s campaign has spent almost nothing in the state on advertising and he has only made one visit to the Philadelphia area since September. Obama, whose campaign has spent more than $5 million in advertising in the state since May, has only visited twice since July.

Declaring that the state is within reach, pro-Romney political action committees say they’re launching television, radio and Web ads. Romney’s campaign is dispatching surrogates like son Tagg Romney and Florida U.S. Sen. Marco Rubio.

— William Douglas, Washington Bureau

NORTH CAROLINA (15 electoral votes)

North Carolina is a battleground state even without the major presidential candidates. Obama has not been back since the Democratic National Convention in Charlotte in September, and Romney has made only one post-convention stop — mainly for a photo op with the Rev. Billy Graham at his mountain home in Montreat.

But the Romney campaigned failed to accomplish its goal of taking North Carolina out of play. Numerous polls show that while he has a slight lead, the race here is within the margin of error.

Even without the candidates, North Carolina is politically contested territory — with some $70 million in TV advertising, robo-calls from Romney and running mate Rep. Paul Ryan, and a ground war that attracted hundreds of volunteers from surrounding Southern states.

Already, 1.4 million people have cast their ballots since early voting began Oct. 18, with voting among African-Americans up 23 percent over 2008.

The state, which Obama won by a slim 14,000-vote margin in 2008, has always been regarded as the most difficult of the battleground states for the president, given its red state heritage and its 9.6 percent unemployment rate. But on the ground in North Carolina, this does not look like a settled matter.

— Rob Christensen, The (Raleigh, N.C.) News & Observer

MICHIGAN (16 electoral votes)

Both candidates have advantages here. Romney’s family has deep roots in the state, where his father was governor from 1963 to 1969 and his brother is still active in state affairs. Romney has also won the state’s Republican presidential primary twice.

Obama was thought to have the more important edge. He boasts that he pushed the auto bailout that sparked the domestic industry’s comeback and boosted the state’s ailing economy, while Romney advocated bankruptcy for the ailing car companies. Michigan’s unemployment rate, 9.3 percent in September, was well above the national average, though far from the 14.2 percent peak of August 2009.

“We’re doing better, but the state is still in pretty bad shape,” said Bill Ballenger, editor of Inside Michigan Politics, a nonpartisan newsletter.

He said that voters are taking a serious look at Romney since his performance at the first debate. What could make a difference is a serious last-minute push by the Romney forces. A poll last week by Foster McCollum White Baydoun, Michigan-based pollsters, showed the race to be a virtual tie.

— David Lightman, Washington Bureau

OHIO (18 electoral votes)

Perhaps more than any other swing state, Ohio means everything for Romney and Obama. For Romney, it’s a must-have, and for Obama, capturing the state would make it nearly impossible for his rival to devise a winning path.

Obama once had a comfortable lead, until his poor performance in the first presidential debate. A Quinnipiac poll on Wednesday still had him up by 5 percentage points, and polls suggest women may hold the key to victory. While Romney has significantly narrowed the gender gap nationwide, a recent poll conducted for Ohio newspapers found that Obama holds an 11 percentage point lead over Romney among Ohio women. The state’s men prefer Romney over the president by a 12 percentage point margin.

Ohio’s unemployment rate has been lower than the national average, but that hasn’t stopped the economy from being the top issue. Obama has been trumpeting his backing of the federal auto bailout for saving jobs in the state, where one in eight Ohio jobs is linked to the auto industry.

Romney sought to dent Obama’s auto claim with a television ad aired in the Toledo and Youngstown markets suggesting that Chrysler, which was purchased by Italians, plans on building its Jeep brand in China. Obama’s campaign quickly responded, noting that the ad doesn’t mention that Chrysler is keeping and expanding its North America Jeep building operations — including in Toledo — while exploring expansion into China. Auto executives also criticized the Romney ad.

— William Douglas, Washington Bureau

WISCONSIN (10 electoral votes)

Romney has surged in Wisconsin the last few weeks, raising the possibility he could be the first Republican presidential nominee to win the state since 1984.

Obama had been ahead, but his advantage started to slip after his rough outing in the first presidential debate. Now polls show the candidates nearly even in Wisconsin, which got lots of candidate attention this week.

The state has a struggling economy and voters are bombarded with political ads either blaming Obama for the economy or touting his efforts. The Green Bay media market is among the most saturated with political ads in the country.

Few undecided voters remain, said David Canon, a political science professor at the University of Wisconsin-Madison. “We’re an incredibly polarized state right now and a very activated state in terms of politics,” he said. “I would be shocked if more than 4 percent were undecided.”

— Sean Cockerham, Washington Bureau

IOWA (6 electoral votes)

Obama hasn’t trailed in the RealClearPolitics.com poll average for more than a year, but here’s a wild card: The Des Moines Register’s surprise endorsement of Romney.

The newspaper remains an influence in a state that gave Obama a 9 percentage point victory in 2008.

“The Register endorsement is unusual, but at most it will move molehills rather than mountains,” said political science professor Dennis Goldford at Drake University in Des Moines. “Still, if the race is as close as it seems, it could move enough undecideds to Romney to make a difference.”

He said that Romney could further benefit by statewide campaigns involving the controversial decision to allow same-sex marriage in the state because opposition to the court ruling might increase conservative turnout.

— David Helling, The Kansas City Star

NEVADA (6 electoral votes)

Perhaps no state was harder hit by the recession than Nevada, a crucial test of Obama’s economic policies four years after he carried the state by more than 12 percentage points.

The foreclosure crisis lingers in and around Las Vegas and the northern cities of Reno and Sparks, while statewide unemployment hovers around 12 percent, highest in the nation.

Still, Obama is narrowly favored. He’s benefited from a well-organized Democratic political apparatus in Nevada, while Romney has been forced to work around a fractured state Republican Party to mobilize voters. Republicans, outnumbered by more than 100,000 active voters in 2008, have reduced the Democrats’ advantage. But Democrats have in recent months regained much of that ground.

— David Siders, The Sacramento Bee

COLORADO (9 electoral votes)

Republican presidential candidates carried Colorado in nine of 10 elections before Obama won the state in 2008. An expanding Latino population and an influx of young people from California and other Democratic-leaning states have reshaped the political landscape. The Colorado electorate is nearly evenly divided now — one-third each Republican, Democratic and unaffiliated — and the race is a virtual tie.

The election here is likely to be decided by the relatively high proportion of unaffiliated voters in the Denver suburbs and along the Front Range of the Rocky Mountains. They tend to be socially moderate, with libertarian, if not conservative, fiscal leanings.

“It’s definitely running on a razor’s edge right now,” said Kyle Saunders, an associate professor of political science at Colorado State University.

“I really would call it a coin flip.”

— David Siders, The Sacramento Bee