President Obama is struggling to persuade voters that he deserves to win re-election based on his handling of the economy, but his empathy and personal appeal give him an edge over Mitt Romney in Ohio, Florida and Pennsylvania, according to Quinnipiac University/New York Times/CBS News polls.


The contours of a deeply competitive presidential race, with three months remaining until the election, are highlighted in the new surveys of likely voters in the three battleground states. Mr. Romney drew fairly even with Mr. Obama when voters were asked about managing the nation’s financial situation, but his candidacy remains tested by concerns over his business background and his reluctance to release more of his tax returns.


The polls in the three states, all of which Mr. Obama carried in 2008, offer a window into challenges and opportunities for both candidates as August begins and they prepare for their nominating conventions and the general election fight. Most paths to victory that the campaigns are pursuing include winning at least two of the states.


While independent voters break strongly for Mr. Obama in Pennsylvania, a state that Mr. Romney has been trying to make more competitive, they are closely split in Florida and Ohio. Of the coalition that Mr. Obama built to win the White House, independent voters remain a hurdle, with a little more than half in Florida and Ohio saying they disapprove of his job performance.


But a torrent of television advertising in the states, particularly in Ohio and Florida, appears to be resonating in Mr. Obama’s quest to define his Republican rival. The polls found that more voters say Mr. Romney’s experience was too focused on making profits at Bain Capital, the private equity firm he led, rather than the kind of experience that would help create jobs.


A snapshot of the race, taken during a burst of summer campaigning, found that Mr. Obama holds an advantage of 6 percentage points over Mr. Romney in Florida and Ohio. The president is stronger in Pennsylvania, leading by 11 percentage points. The margin of sampling of error is plus or minus three percentage points in each state.


The New York Times, in collaboration with Quinnipiac and CBS News, is tracking the presidential contest in six states through polls over the next three months. In addition to Ohio, Florida and Pennsylvania, which have a combined 67 electoral votes, surveys will be taken in Colorado, Wisconsin and Virginia, which have 32 electoral votes.


Four years ago, Mr. Obama won all six states. Mr. Romney is campaigning in each state, with his strategists seeing the efforts in Pennsylvania and Wisconsin as the most ambitious. Those two states, which have voted for the Democratic presidential candidate over the last two decades, are considered firewalls, and an erosion of support would signal trouble for the president.


The polls found that Mr. Obama faces substantial hurdles of his own, most of them rooted in the electorate’s deeply pessimistic outlook on the economy. By double-digit margins, voters in each state say his policies would hurt, rather than help, their personal financial situation if he won re-election, a worrisome sign considering the economy is ranked as voters’ chief concern.


Still, more than half of voters in each state also say the administration’s actions are either slowly improving the economy or will, if given more time.


“Romney does have business experience, but I wonder if his business experience would benefit the country or might harm it,” said Peg Pagano, 72, a retiree in Holland, Pa., in a follow-up interview. “He was in business in order to make a profit. There’s nothing wrong with that, but how would that help the country? I feel Obama needs to be given another four years.”


In all three states, most women say they prefer Mr. Obama. About half of female voters in Florida back him, while his support is even stronger in Ohio and Pennsylvania, where nearly 6 in 10 women say they favor him. In Ohio, men prefer Mr. Romney, while they are more closely split in Florida and Pennsylvania.