ATLANTA — President Obama escalated his campaign’s latest line of attack on Mitt Romney’s business career on Tuesday, telling audiences at a series of fund-raising events that when it came to job creation, the former Massachusetts governor excelled more at creating them overseas than in America.

A news article last week about how Mr. Romney’s old private equity firm moved jobs overseas prompted a carefully parsed response from the Romney camp. Seeking to capitalize on it, Mr. Obama — and a team of campaign aides, operatives and surrogates — took to the airwaves, microphones and the Internet to call his rival out of touch.
At a fund-raiser in Atlanta, Mr. Obama derided Mr. Romney’s advisers for trying to distinguish between “off-shoring” and outsourcing. The president added cheerfully, “I’m not kidding, that’s what they said.”
As the audience laughed, he delivered his punch line: “Those workers who lost their jobs, they don’t know the difference.”
Over in the Romney camp, the response was swift and scathing. “If President Obama had even half of Mitt Romney’s record on jobs, he’d be running on it,” Andrea Saul, a Romney spokeswoman, said in an e-mail statement. “But President Obama has the worst record on jobs and the economy of any president in modern history, which is why he is running a campaign based on distractions, not solutions.”
Mr. Romney has been hurt by this line of attack in the past. During the early nominating contests, he struggled against criticisms like these on his record at Bain Capital, the private equity firm he co-founded.
Romney aides vigorously dispute many of the assertions published in The Washington Post, which called Bain Capital “pioneers” of outsourcing, and are meeting with the newspaper on Wednesday to ask for a retraction. The campaign has said the “fundamentally flawed” article failed to distinguish between jobs outsourced to companies within America, jobs sent overseas and jobs created overseas.
Privately, Romney aides said they were not too worried about the assaults on Bain. Their plan is to welcome any discussion that deals with Mr. Romney’s business background, and simply refocus the conversation on what they believe is his strength: that his time in the private sector has prepared him to fix the economy.
“The backhanded side of this is a compliment — that Romney’s business acumen and history is relevant and is a legitimate credential,” said an adviser, speaking on the condition of anonymity in order to talk more freely about the campaign’s internal thinking. “They’re saying that his business background is something you ought to pay attention to, and on that level, we like it.”
But the Obama campaign seems to be scenting blood on the outsourcing issue, and Obama aides were hard at work calling attention to it. In Waterloo, Iowa, Vice President Joseph R. Biden Jr. called Mr. Romney “a job creator — in Singapore. And China. And India.” His remarks were quickly posted on Twitter by the Obama campaign. Mr. Biden’s attack prompted a quick rebuke from the Romney campaign, which sent an e-mail to reporters saying that Mr. Biden was trying to “distract voters from the president’s disastrous economic record.”
The Obama campaign also unveiled new TV ads in three swing states, which accuse Mr. Romney of being a possible “Outsourcer in Chief.”
Two of the 30-second ads, showing in Iowa and Virginia, focus on the Washington Post article. The third ad, in Ohio, takes a page out of Mr. Romney’s playbook by demonizing China, much as Mr. Romney, the presumptive Republican nominee, has been doing.
“Romney’s never stood up to China,” the ad says. “All he’s done is send them our jobs.”
Mr. Obama was closing out a two-day, high-intensity fund-raising swing that took him to four states and that should raise up to $5 million, aides said. In Atlanta, he attended two fund-raisers before flying to Miami for two more, including one featuring the Latin music star Marc Anthony. But even as Mr. Obama was hauling in the cash to Democratic coffers, he warned Democrats that they were facing a fund-raising behemoth in the form of Republican “super PAC” donations.
At one event, the president began, “You’ve got Mr. Romney,” only to be interrupted by boos.
“No,” Mr. Obama continued, as if he did not like the idea of people booing the man he was about to criticize, “Mr. Romney is a patriotic American, he’s got a beautiful family, he’s been very successful all his life.”
Then, having dispensed with the perfunctory praise, Mr. Obama launched into all the reasons not to vote for Mr. Romney.
Mr. Romney, appearing Tuesday in Salem, Va., kept the focus on the president’s record, and offered a preview of his likely responses when the Supreme Court rules later in the week on Mr. Obama’s health care law.
“If Obamacare is not deemed constitutional, then the first three and a half years of this president’s term will have been wasted on something that has not helped the American people,” Mr. Romney said. “If it is deemed to stand, then I’ll tell you one thing: We’re going to have a president, and I’m that one, that’s going to get rid of Obamacare. We’re going to stop it on Day 1.”
This has been one of Mr. Romney’s most reliable applause lines, and his comments underscored that he plans to attack Mr. Obama on health care, regardless of the court’s ruling.
Helene Cooper reported from Atlanta, and Ashley Parker from Salem, Va.