WASHINGTON -- Eleven states are likely to decide whether President Barack 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 demographics; and economies that are recovering slowly.The biggest prize is Florida, whose 29 electoral votes would give the winner more than 10 percent of what he needs for election. So far, the battle for the Sunshine State is a virtual tie.The states to watch first on election night are Virginia and North Carolina.Both went Democratic in 2008 for the first time in decades, but they show signs of inching back to the Republican side. Also worth eyeing is New Hampshire. In a close race, its four electoral votes could matter, and polls suggest that either candidate could win.Move west, and there's the most reliable bellwether, Ohio.No Republican has ever won the presidency without it, and no one has won the presidency, period, without Ohio since 1964.Obama's up by a healthy average of 4.6 points in recent statewide polls.Should the race remain tight Tuesday night, attention will turn farther west, first to Iowa and Wisconsin and then to the night's final battlegrounds, Colorado and Nevada.Each has seen increases in their Hispanic populations, and surveys show that Latinos overwhelmingly favor Obama. But will they turn out?The fight for the sliver of undecided voters in the battleground states is unusually fierce. Estimates are that the two campaigns and their parties will each raise more than $1 billion.Obama's forces have opened more than 100 campaign offices in both Florida and Ohio.Romney's camp boasts that it has knocked on more than 2 million doors in Ohio.But going into the final weekend of the campaign, all the polls agree: It's too close to call.More on the key states:Florida(29 electoral votes)The latest surveys show a tight race. Lines for early voting, which ends Saturday, remain long. And there could be up to 2 million absentee ballots to count. As of Thursday, Democrats held a 59,000-ballot advantage over Republicans in votes cast before Election Day. But Republicans are confident that they will finish strong.New Hampshire(four electoral votes)New Hampshire is the smallest of the battleground states, but it's almost evenly divided between the parties, so it could be a key steppingstone on the path to 270. Obama won the state soundly in 2008, but recent polls show him with an increasingly slim lead. 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 tossup.In 2008, Obama became the first Democratic presidential candidate to carry the state in more than four decades. But this year, surveys give Virginia the distinction of being the closest battleground state in the nation.Pennsylvania(20 electoral votes)After being largely ignored through the general election season, Pennsylvania has gotten attention from Romney recently. Is it 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? Gov. Tom Corbett is a Republican, and the Legislature is under Republican control. But the GOP's recent presidential candidates have had little success.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 to visit the Rev. Billy Graham. But the Romney campaign failed to accomplish its goal of taking North Carolina out of play.Numerous polls show that while he has a slight lead, the race is within the margin of error.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 pushed the auto bailout that sparked the industry's comeback.Ohio(18 electoral votes)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 had a comfortable lead until his poor performance in the first presidential debate.Wisconsin(10 electoral votes)Romney has surged in Wisconsin the last few weeks, raising the possibility that he could be the first Republican presidential nominee to win the state since 1984. Obama had been ahead, but his advantage slipped after the first debate.Now polls show the candidates nearly even.Iowa(six 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.Nevada(six 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. Still, Obama is only narrowly favored.Colorado(nine electoral votes)Republican presidential candidates carried Colorado in nine of 10 elections before Obama won the state in 2008. The race is a virtual tie.