Campaign 2012 packed frantic suspense to the finish, with Vice President Joe Biden flying in unannounced next to Republican Mitt Romney's campaign plane in battleground Ohio on Tuesday even as voters across the country were deciding who would win the White House.

President Barack Obama stayed in hometown Chicago, reaching out to swing-state voters on the phones and via satellite while the other three men on the rival tickets had a high noon face-off near the shore of Lake Erie.

Romney and running mate Paul Ryan had scheduled the stop together just on Monday, and Biden's plane arrived between the two to play defense in the state that's critical to the victory plan for both sides. The vice president rolled off the tarmac without comment to the surprised media traveling on his plane, just as Ryan's charter was pulling in for a landing.

Romney said the eleventh-hour campaigning was meant to leave him with no regrets.

"I can't imagine an election being won or lost by, let's say, a few hundred votes and you spent your day sitting around," Romney told Richmond radio station WRVA earlier in the day. "I mean, you'd say to yourself, 'Holy cow, why didn't I keep working?' And so I'm going to make sure I never have to look back with anything other than the greatest degree of satisfaction on this whole campaign."

Meanwhile, Americans headed into polling places in sleepy hollows, bustling cities and superstorm-ravaged beach towns deeply divided. All sides are awaiting, in particular, a verdict from the nine battleground states whose votes will determine which man can piece together the 270 electoral votes needed for victory.

Obama has more options for getting there. So Romney decided to make the late dash to Cleveland and Pittsburgh on Tuesday while running mate Ryan threw in another stop in Richmond, Va.

Obama visited a campaign office close to his home in Chicago and was met by applause and tears from volunteers before he picked up a phone to call voters in neighboring Wisconsin. He told reporters that the election comes down to which side can get the most supporters to turn out.

"I also want to say to Gov. Romney, 'Congratulations on a spirited campaign.' I know his supporters are just as engaged, just as enthusiastic and working just as hard today," the president said.

Romney was asked on WTAM radio in Cleveland whether he agreed that voters always get it right in the end. "I won't guarantee that they'll get it right, but I think they will," Romney replied.

Biden and his wife, Jill Biden, were among the first voters on Tuesday in at a polling place in Greenville, Del., Biden's home state. Smiling broadly, Biden waited in line with other voters and greeted them with a handshake. Outside he sent a message to people across the country who may encounter crowded polling places. "I encourage you to stand in line as long as you have to," he told television cameras.

The Obamas had voted last month in an effort to encourage supporters to vote early. The men on the GOP ticket each voted with their wives at their side Tuesday morning in their hometowns — Romney in Belmont, Mass., and Ryan in Janesville, Wis. — then headed to meet in Cleveland for some retail politicking at restaurants and other unannounced stops. The last-minute nature of the swing made it too difficult to arrange a big public event, but their hope was their joint visit would get local news coverage that might translate to more support.

Both sides cast the Election Day choice as one with far-reaching repercussions for a nation still recovering from the biggest economic downturn since the Great Depression and at odds over how big a role government should play in solving the country's problems.

"We can make sure that we make even greater progress going forward in putting folks back to work and making sure that they've got decent take-home pay, making sure that they have the health insurance that they need, making sure we're protecting Medicare and Social Security," Obama said in an interview broadcast Tuesday on "The Steve Harvey Morning Show." ''All those issues are on the ballot, and so I'm hoping that everybody takes this seriously."

Romney argued that Obama had his chance to help Americans financially and blew it. "If it comes down to economics and jobs, this is an election I should win," Romney told Cleveland station WTAM.

With both sides keeping up the onslaught of political ads in battleground states right into Election Day, on one thing, at least, there was broad agreement: "I am ready for it to be over," said nurse Jennifer Walker in Columbus, Ohio.

It wasn't just the presidency at stake Tuesday: Every House seat, a third of the Senate and 11 governorships were on the line, along with state ballot proposals on topics ranging from gay marriage and casino gambling to repealing the death penalty and legalizing marijuana. Democrats were defending their majority in the Senate, and Republicans doing likewise in the House, raising the prospect of continued partisan wrangling in the years ahead no matter who might be president.

If past elections are any guide, a small but significant percentage of voters won't decide which presidential candidate they're voting for until Tuesday. Four percent of voters reported making up their minds on Election Day in 2008, and the figure was 5 percent four years earlier, according to exit polls. In Washington-Lee High School in Arlington, Va., hundreds of voters were in line shortly after the polls opened at 6 a.m. and had to wait more than an hour to cast their ballot.

The forecast for Election Day promised dry weather for much of the country, with rain expected in two battlegrounds, Florida and Wisconsin. But the closing days of the campaign played out against ongoing recovery efforts after Superstorm Sandy. Election officials in New York and New Jersey scrambled to marshal generators, move voting locations, shuttle storm victims to polling places and take other steps to ensure everyone who wanted to vote could do so.

In New York City, authorities planned to run shuttle buses every 15 minutes Tuesday in storm-slammed areas to bring voters to the polls. In Ocean County along the New Jersey coast, officials hired a converted camper to bring mail-in ballots to shelters in Toms River, Pemberton and Burlington Township.

"This is the happiest vote I ever cast in my life," said Annette DeBona as she voted for Romney in Point Pleasant Beach, N.J. The 73-year-old restaurant worker was so worried about not being able to vote that she called the police department several days in advance, as well as her church, to make absolutely sure she knew where to go and when.

Renee Kearney, of Point Pleasant Beach, said she felt additional responsibility to vote this Election Day. The 41-year-old project manager for an information technology company planned all along to vote for Obama, but said her resolve was strengthened by his response to Sandy.

"It feels extra important today because you have the opportunity to influence the state of things right now, which is a disaster," Kearney said.

Election Day came early for more than a third of Americans, who cast ballots days or even weeks in advance.

An estimated 46 million ballots, or 35 percent of the 133 million expected to be cast, were projected to be early ballots, according to Michael McDonald, an early voting expert at George Mason University who tallies voting statistics for the United States Elections Project. None of those ballots were being counted until Tuesday.

Obama, who voted 12 days early, was sure to observe his Election Day ritual of playing pickup basketball with friends and close advisers. The one time he skipped the tradition, he lost the New Hampshire primary in 2008.

"We won't make that mistake again," said senior adviser Robert Gibbs.

The election played out with intensity in the small subset of battleground states: Colorado, Iowa, Florida, New Hampshire, Nevada, North Carolina, Ohio, Virginia and Wisconsin. Romney's late move to add Pennsylvania to the mix was an effort to expand his options, and Republicans poured millions into previously empty airwaves there.

In the campaign's final hours, voters around the country echoed the closing arguments of the two presidential candidates.

Jim Clark, a 42-year-old computer administrator from Topeka, Kan., is a registered Republican who voted for Obama in 2008, seeking change. But he voted Tuesday for Romney after losing a full-time job two years ago and working temporary assignments since then.

"I'm just ready for a change," Clark said. "It's tougher for me, personally. The economy has not improved."

But 35-year-old Tamara Johnson, of Apex, N.C., said she was sticking with Obama even though she's not as enthusiastic as four years ago.

"I wouldn't say it's easy," said the 35-year-old customs broker as she voted at the Wake County Firearms Education & Training Center. "I have to take into account everything that's been going on and everything I feel will go on. Not just for myself and the future but for my kids. And I think I made the right choice."