COLUMBUS, Ohio - Even with all the peaks and valleys and supposed game-changing moments of the 2012 presidential campaign, there never really was any doubt about who would decide the next occupant of the White House. The winner will be crowned by a trio of Midwest battlegrounds, two southern tossups and a pair of states with few electoral votes of their own.

President Obama and Mitt Romney pumped unprecedented resources -- about $2 billion -- into what is now the most expensive political campaign in history. But much of that money and effort over the past year focused on a small, exclusive group of states -- Virginia, Florida, Ohio, Wisconsin, Iowa, New Hampshire and Colorado, which together will decide this razor-thin race.

By the time Obama and Romney were wrapping up their campaigns Monday, Obama essentially conceded North Carolina. And Romney had all but given up on Nevada, even as he jetted into Democratic Pennsylvania to expand the playing field.

Maybe the only thing that's certain in Tuesday's election, campaign operatives and strategists said, is that it won't resemble Obama's 2008 victory. Four years ago, on the brink of making history as America's first black president, Obama's message of hope and change electrified the electorate and drew record numbers of young people to the polls.

Obama's current campaign, his last, is much tighter, so close that some question whether Tuesday could end without a clear idea of who won, something that last happened in 2000.

Despite close polls, Democrats say Obama will ultimately prevail if he can turn out young and minority voters.

"Romney has both a narrow message and narrow path to victory," said Democratic pollster Margie Omero. "He's basically put all his marbles in running up the score with white men. It's not a good long-term or short-term strategy."

For Romney, winning depends on his ability to turn out voters in the battleground states and to cut into Obama's lead among women, particularly suburban women. Conservatives say he has momentum on his side.

"Republican intensity is surging, while Democrat excitement is ebbing," said Brian Donahue, a GOP strategist. "Heading into Election Day, 51 percent of Republicans and 44 percent of Democrats say they're excited about this election. This is a major falloff from Obama's 2008 intensity numbers."

Many voters, meanwhile, are just eager for the race to end, particularly in battlegrounds like Ohio that for months endured seemingly endless barrages of campaign ads. During the lunch rush at a central Ohio deli Monday, an Obama commercial appeared on the TV, followed by a Romney ad and then a pair of spots for Ohio's U.S. Senate race.

"Glad they took a break for actual programming," Ryan Baker quipped over a Reuben sandwich. "California sounds pretty good right now. I'm glad my vote actually means something, but this is unbearable."

Yet, even though the race is down to a select group of states -- almost all of them obvious targets for the candidates from early on in the race -- it's unclear what the polarized voters will decide.

"Even if you squeezed me hard, I'd say it's 50-50," Charles Walcott, an expert on the presidency at Virginia Tech, said of Romney's and Obama's chances in Virginia. "There are just so many factors in play. Only time will tell."