The comparison doesn't reflect contributions to joint campaign committees in which donations for Obama or Romney are pooled with money for party groups at big-ticket events. A June 12 event in Philadelphia was said by organizers to have produced about $2 million for one such group, the Obama Victory Fund.
Romney, who was an early contender for the 2008 Republican nomination won by McCain, took in $2.35 million through his Romney for President committee as of May 31 - $494,000 less than Obama.
But he was doing almost twice as well as McCain's campaign at a similar point in the election cycle. McCain's fund, as of May 2008, had raised $1.25 million.
The Philadelphia region, with its eight-county population of 5.5 million, has long been a major source of cash for presidential contenders of both parties. But the region's concentration of labor unions, trial lawyers, and minority voters - key elements of the Democratic coalition - has made it especially key for Democrats.
Romney's gains over McCain reflect greater enthusiasm this year among GOP donors that their party can win the White House, said Charles G. Kopp, a Republican fund-raiser in Philadelphia.
"More Republicans in the eight-county Philadelphia region believe Romney will win in 2012 than believed McCain would win in 2008," he said.
Obama Democrats - at least until Thursday's victory on health care in the U.S. Supreme Court - have felt a bit battered by the economy's slow rebound, even though polls show Obama leading in Pennsylvania, a vital swing state.
With the court's decision to uphold the Obama health-care law, Democrats could get a fresh shot of adrenaline. But so, too, could Republicans motivated by Romney's vow to revoke the law if elected president.
Alan C. Kessler, a Democratic fund-raiser in Philadelphia, said Wednesday that today's economy had made it a challenge for both sides to scour up campaign funds.
For Obama enthusiasts, he said, it would be hard to compare anything to the heady days of 2008.
"I would never say the enthusiasm is not the same," Kessler said. ". . . But four years ago it was a movement as much as it was a campaign. It was historic."
Almost all of Obama's key fund-raisers in the region joined together for the June 12 event, held at the Franklin Institute. A similar event in 2008 was held later in the year - in October.
"We raised about $2 million," said Comcast Corp. executive David L. Cohen, who coordinated the event. "As of today, we're a touch below. Over the next 30 to 60 days, we are going to go above as we continue to collect checks."
The FEC data show that Romney's biggest gains over McCain at this point in the cycle have been in Philadelphia's Pennsylvania suburbs, where he has raised $1.89 million, doubling McCain's $948,000 at a comparable point.
The Pennsylvania suburbs were the only part of the region in which Romney led Obama. He was not quite $283,000 ahead.
Obama led by $680,000 in Philadelphia and $96,000 in South Jersey.
McCain, in 2008, struggled with his finances. He went back and forth on whether to accept public campaign money, which restricts private donations. He ultimately decided to take the public money.
Contributions to Obama for America through May of this year were down across the board from four years ago - down 35 percent in the Pennsylvania suburbs, 27 percent in Philadelphia, and 14 percent in South Jersey.
Jen Austin, Obama's campaign spokeswoman in Pennsylvania, said this reflected a change in fund-raising strategy.
In May 2008, Obama was still wrapping up the Democratic nomination. He had just lost the Pennsylvania primary, in which most top party fund-raisers were allied with Hillary Rodham Clinton. This year, with no party opposition, Obama has been free since early on to combine his fund-raising with the victory fund, Austin said.
"The campaign is organized differently than it was in 2008, so any comparison of numbers that do not include donations coming into the Obama Victory Fund are not an accurate way to reflect President Obama's fund-raising in the area," Austin said.
"When one makes an accurate comparison of the money that Obama and his campaign have raised in 2012 in the eight-county area, it is more than was raised at the same time in 2008," Austin said.
But the Republicans likewise have a joint committee, the Romney Victory Fund, which is collecting donations on behalf of the former Massachusetts governor.
"Things are different now than they were four years ago" said Kate Meriwether, Romney's state spokeswoman. "I think we're doing a pretty good job hitting the ground hard here in Pennsylvania."
Contact Tom Infield at 610-313-8205 or firstname.lastname@example.org, or follow on Twitter @tinfield.