U.S. President Barack Obama notched a win in the battle for campaign cash for the first time in four months, raising more money than Mitt Romney in August as the candidates gear up for the final stretch of their closely contested election race.

With Election Day less than two months away, Obama is also picking up a lead of a few percentage points over Romney in several daily tracking polls, but the race remains a very tight one that most voters say depends on which candidate they feel is best prepared to revive the struggling U.S. economy.

Obama appeared to have benefited from last week's Democratic National Convention and speeches by his wife, first lady Michelle Obama, and former President Bill Clinton, but post-convention bumps in poll numbers tend to be fleeting.

Game of numbers

The Mitt Romney campaign's pollster issued a memo to reporters on Monday advising them not to get "too worked up" about numbers suggesting that Barack Obama had opened up a lead in the race since the Republican and Democratic conventions.

"While some voters will feel a bit of a sugar high from the conventions, the basic structure of the race has not changed significantly," Neil Newhouse wrote.

The memo diverged from traditional number-crunching, usually the domain of pollsters, by delving into the Romney campaign's strategy.

Obama raised more than $114 million in August, while Romney brought in just over $111 million, according to numbers released early Monday by the rival campaigns. It's a sharp increase for the president, who raised $75 million in July.

While incumbent presidents normally raise more money than their challengers, Obama and his supporters have struggled to match the fundraising prowess of Romney and his allies. Despite Obama's fundraising advantage in August, Romney has collected more than $100 million for the third straight month, and the figure represents his best one-month fundraising total. And the Republican nominee has socked away more money for the general election campaign.

Romney showed signs of taking a new, more centrist tack toward health care and defence spending as he starts the next leg of his campaign with a Monday rally in Ohio, a pivotal battleground state in the state-by-state battle for the presidency. Obama, who spent the weekend campaigning in Florida, is scheduled to be at the White House.

After weeks of pushing conservative Republican themes leading up to the party convention in Tampa, Florida, Romney's less partisan tone comes as the race shifts toward the Nov. 6 election, which is expected to be decided in fewer than 10 states where neither Romney nor Obama has a significant advantage.

Differences on health-care reform

Romney's views on health care are starkly different than Obama's. They include major changes to the federal Medicare insurance program for Americans over age 65. Adopting the position of his conservative running mate Rep. Paul Ryan, Romney has called for giving retirees a government payment that they could use to spend on traditional Medicare or a private insurance plan.

Romney said in an interview that aired Sunday that he would keep in place elements of Obama's landmark federal health-care law signed in 2010. On NBC's "Meet the Press," Romney said: "I'm not getting rid of all of health care reform. Of course, there are a number of things that I like in health care reform that I'm going to put in place."

Campaign aides said Romney's endorsement of parts of Obama's Affordable Care Act was consistent with his previous position that those who haven't had a gap in coverage shouldn't be denied coverage.

'No American should have to spend their golden years at the mercy of insurance companies.'——U.S. President Barack Obama

The comments brought renewed attention to the similarities between the bill Obama signed and the one Romney championed when he was governor of Massachusetts.

Romney aides dismissed the idea that the candidate's comments about the defence cuts or health care were an effort to appear less partisan with the race for undecided voters now under way.

Romney also faulted congressional Republicans for going along with the White House on a budget deal that has set up automatic spending cuts that include huge reductions in defence spending — a deal his running mate helped steer.

Obama on Sunday focused Floridians' attention on the Republican ticket's stand on Medicare, an issue that's been more favourable to Democrats.

At a rally in Melbourne, Florida, Obama told about 3,000 voters that Romney wants insurers to profit at the expense of working Americans.

"No American should have to spend their golden years at the mercy of insurance companies," he said.

After Ohio, Romney is heading to Nevada and Florida later this week. The Romney campaign is airing television advertisements for the first time in Wisconsin this week, hoping to force Obama to play defence in a state Democrats have carried in every election since 1988.

Congress, meanwhile, returns from recess Monday, and faces the task of preventing a government shutdown when the budget year ends Sept. 30 amid election-season politicking. Congress is expected to pass a six-month temporary spending bill to finance the government's day-to-day operations, kicking bigger fiscal battles down the road.