WASHINGTON - President Barack Obama and Republican challenger Mitt Romney engaged in frantic get-out-the-vote efforts and made final pleas to voters Monday in a sprint through battleground states that will determine who wins their agonizingly close White House race.

Both candidates sought to generate strong turnout from supporters and to sway independent voters to their side in the last hours of a race that polls showed was deadlocked nationally. Obama had a slight lead in the eight or nine battleground states that will decide the race on Election Day.

The latest Reuters/Ipsos national poll of likely voters, a daily tracking poll, gave Obama a slight edge, with 48 percent support compared to Romney's 46 percent. The difference was within the 3.4 percentage point margin of era.

Obama was up 4 percentage points in must-win Ohio, 50 percent to 46 percent, and held slimmer leads in Virginia and Colorado. Romney led in Florida by 1 percentage point, the poll found.

The President, with a final-day itinerary that included stops in Wisconsin, Ohio and Iowa, urged voters to stick with him and trust that his economic policies are working. Traveling with him was rocker Bruce Springsteen.

"Ohio, I'm not ready to give up on the fight. I've got a whole lot of fight left in me and I hope you do too," Obama told supporters in Columbus, Ohio.

Romney's final day included stops in Florida, Virginia, Ohio and New Hampshire. He pledged that he would handle the economy better than Obama and jabbed his opponent for blaming Republican predecessor George W. Bush for the weak economy.

"I won't waste any time complaining about my predecessor. And I won't spend my time trying to pass partisan legislation rather than working to help America get back to work," Romney said in Fairfax, Virginia.

The candidates are seeking to piece together the 270 Electoral College votes needed for victory in the state-by-state battle for the presidency.

Despite the close national opinion polls, Obama has an easier path to victory: If he won the three states he was visiting on Monday - Wisconsin, Ohio and Iowa - then he would likely carry the day.

Ohio could be decisive

All eyes were on the Midwestern state of Ohio, whose 18 electoral votes could be decisive. Romney, looking for any edge possible, planned last-second visits today to both Ohio and Pennsylvania, aides said.

Visits to the areas around Cleveland and Pittsburgh would be aimed at driving turnout.

And the Pittsburgh stop could be as much about Ohio as Pennsylvania, since many in eastern Ohio watch Pittsburgh television.

Romney's path to the White House becomes much harder should he lose Ohio. The state has been leaning toward Obama - its unemployment rate is lower than the 7.9 percent national average and its heavy dependence on auto-related jobs meant the bailout to auto companies that Obama pursued in 2009 is popular.

Both campaigns expressed confidence that their candidate would win, and there were enough polls to bolster either view.

There were clear signs that Obama held an edge.

A CNN/ORC poll, for instance, showed him up in Ohio by 50 percent to 47 percent.

Challenges ahead

Whoever wins will have a host of challenges to confront. The top priority will be the looming "fiscal cliff" of spending cuts and tax increases that would begin with the new year.

The balance of power in Congress also will be at stake today, with Democrats now expected to narrowly hold their Senate majority and Republicans favored to retain control of the House.