McCain, too, promised to turn the page of the era of George W. Bush, and he warned about his opponent's intentions. "Sen. Obama is in the far left lane" of politics, he said. "He's more liberal than a guy who calls himself a Socialist and that's not easy."
Republican running mate Sarah Palin was even more pointed as she campaigned in Ohio. "Now is not the time to experiment with socialism," she said. "Our opponent's plan is just for bigger government."
Late-season attacks aside, Obama led in virtually all the pre-election polls in a race where economic concerns dominated and the war in Iraq was pushed - however temporarily - into the background.
While the overall number of early votes was unknown, statistics showed more than 29 million ballots cast in 30 states and suggested an advantage for Obama. Democrats voted in larger numbers than Republicans in North Carolina, Colorado, Florida and Iowa, all of which went for President Bush in 2004.
Democrats also anticipated gains in the House and in the Senate, although Republicans battled to hold their losses to a minimum and a significant number of races were rated as tossups in the campaign's final hours.
By their near-non-stop attention to states that voted Republican in 2004, both Obama and McCain acknowledged the Democrats' advantage in the presidential race.
The two rivals both began their days in Florida, a traditionally Republican state with 27 electoral votes where polls make it close.
Obama drew 9,000 or so at a rally in Jacksonville, while across the state, a crowd estimated at roughly 1,000 turned out for McCain.
The frontrunner also choked up on the campaign's final day as he told a crowd in North Carolina of the death of his grandmother from cancer. Madelyn Payne Dunham was 86.
"She died peacefully in her sleep with my sister at her side," he said of the woman who had played a large role in his upbringing. "And so there is great joy as well as tears. I'm not going to talk about it too long because it is hard for me to talk about."
McCain and his wife issued a statement of condolence.
One day before the election, no battleground state was left unattended.
But Virginia, where no Democrat has won in 40 years, and Ohio, where no Republican president has ever lost, seemed most coveted. Together, they account for 33 electoral votes that McCain can scarcely do without.
Democratic volunteers in Maryland, a state safe for Obama, called voters in next-door Virginia, where McCain trailed in the polls. The Democratic presidential candidate's visit to Virginia during the day was his 11th since he clinched the nomination.
Unwilling to concede anything, McCain's campaign filed a lawsuit in Richmond seeking to force election officials to count late-arriving ballots from members of the armed forces overseas. No hearing was immediately scheduled.
Several hundred miles away in Ohio - the state that sealed Bush's second term in 2004 - voters waited as long as three hours in line to cast ballots in Columbus, part of heavily contested Franklin County. Poll workers handed out bottles of water to sustain them.
Lori Huffman, 38, a supervisor at UPS Inc., took the day off to vote early for her man, McCain. "It's exciting isn't it?" she asked, gesturing toward the long line of waiting voters.
"This is happening all over the state, from Cleveland to Dayton," said Gov. Ted Strickland, a Democrat trying to deliver his state to Obama.
Obama hoped so, after more than a year building an elaborate get-out-the-vote operation, first for the primary campaign, now for the general election.
The Democrat flew from Florida to North Carolina to Virginia, all states that went Republican in 2004, before heading home to Chicago on Election Eve.
Twenty-one months after he launched his campaign, he allowed, "You know. I feel pretty peaceful ... I gotta say."
On a syndicated radio program, the Russ Parr Morning Show, he said, "The question is going to be who wants it more," he added. "And I hope that our supporters want it bad, because I think the country needs it."
If wanting it were all that mattered, the race would be a toss-up.
McCain, behind in the polls, set out on a grueling run through several traditionally Republican states that he has failed to secure. Florida, Virginia, Indiana, New Mexico and Nevada were on his itinerary, as was Pennsylvania, the only state that voted Democratic in 2004 where he still nursed hopes. His last appearance of the long day, past midnight, was a home state rally in Prescott, Ariz. Obama has been running television commercials in Arizona in the campaign's final days.
The surrogate campaigners included Sen. Hillary Rodham Clinton for the Democrats and former Massachusetts Gov. Mitt Romney for the Republicans. Both lost races for their party's presidential nomination earlier in the year, and both could be expected to try again if their ticket loses the White House.
Not so, President Bush.
Deeply unpopular, the man who won the White House twice was out of public view, an effort to help McCain.
Palin was racing through five Bush states Monday - Ohio, Missouri, Iowa, Colorado and Nevada - in an effort to boost conservative turnout for McCain. The Alaska governor has been a popular draw for many GOP base voters, and already, there was speculation about a future national campaign should Republicans lose in 2008.
Joe Biden, Obama's running mate, campaigned in Missouri, Ohio and Pennsylvania. "We are on the cusp of a new brand of leadership," he assured supporters.
Biden didn't say so, but he was as close to guaranteed a victory as any politician in America. Whatever the fate of the Democratic presidential ticket, he was heavily favored to win a new Senate term from Delaware on Tuesday.
AP writers Nedra Pickler in Jacksonville, Fla., Meghan Barr in Columbus, Ohio, Joe Milica from Lakewood, Ohio, Christopher Clark in Lee's Summit, Mo., and Kristen Wyatt in Denver contributed to this report.