Republican presidential challenger Mitt Romney is stepping up his attacks on President Barack Obama, but growing pressure from across the political spectrum to release more of his personal tax returns threatens to stunt the Republican presidential candidate's momentum as he campaigns across key Midwestern battleground states.
The former Massachusetts governor was intensifying attacks to counter blazing political assaults on his history as the head of a private equity firm and his refusal to release more of his tax returns.
Obama has been trying to keep Romney focused on matters other than the sluggish recovery from the 2008 financial meltdown, even releasing a single-shot TV ad Tuesday that suggests Romney gamed the system so well that he may not have paid any taxes at all for years. Polls show the economy is uppermost in the minds of voters who will go to the polls in November.
The former Massachusetts governor takes his fight against Obama to Ohio on Wednesday, building off fiery speeches in Pennsylvania the day before in which he accused his Democratic opponent of believing the government is more vital to a thriving economy than the nation's workers and dreamers.
"I'm convinced he wants Americans to be ashamed of success," Romney declared Tuesday in the Pittsburgh area as hundreds of supporters cheered him on.
Having spent most of Tuesday courting donors across Texas, Obama has a series of official meetings in Washington ahead of a two-day Florida campaign swing later in the week.
Democrats have pressed for the release of more of Romney's tax returns and hounded the Republican candidate over discrepancies over when he left his private equity firm.
The Obama campaign has also hammered at Romney's business record, especially discrepancies over when he departed as chief of the private equity firm Bain Capital that he co-founded in the 1980s. Romney says his business record is his chief qualification to be president, and it is the source of his vast fortune, estimated at a quarter of a billion dollars.
After being on the defensive for several days, Romney launched an aggressive counterattack this week, punctuated by biting speeches, conference calls and a television ad expected for release Wednesday that accuses Obama of "crony capitalism" and seizes on comments uttered by Obama while campaigning in Virginia last week.
The president, making a point about the supportive role government plays in building the nation, said in part: "Somebody helped to create this unbelievable American system that we have that allowed you to thrive. Somebody invested in roads and bridges. If you've got a business, you didn't build that. Somebody else made that happen."
Obama later added: "The point is, is that when we succeed, we succeed because of our individual initiative, but also because we do things together."
At a Pittsburgh fundraiser Tuesday evening, Romney lashed out at the remark, a strategy his campaign says will be a theme for the week, if not longer.
"It's foolish on its face and shocking that a president of the United States would not understand the power of entrepreneurship and innovation," Romney said. "It is an attack on the very premise that makes America such a powerful economic engine."
The Obama campaign said Romney had distorted Obama's message by taking him out of context. Obama's intended point — one he made again in Texas on Tuesday — was that government plays a role in helping people and businesses succeed by building roads, hiring teachers and firefighters, and looking out for the public good.
For the often-reserved Romney, the fresh attacks marked a substantial escalation in aggression for a candidate who has recently struggled to answer questions about his business career and personal tax returns. The former businessman, who would be among the nation's wealthiest presidents if elected, has so far released just one year of personal income tax returns and promised to release a second.
That's a stark deviation from a tradition created in part by his father, former Michigan Gov. George Romney, who as a presidential candidate in 1968 released 12 years of his own returns.
A defiant Romney has accused the Obama campaign of using the issue to distract voters from the state of the U.S. economy less than four months before Election Day.
But it's unclear if Romney's new strategy will be enough to change the subject, particularly as several prominent Republicans joined Democrats in pushing Romney for more transparency.
Late Tuesday, Texas Gov. Rick Perry — who challenged Romney for the Republican presidential nomination — became the latest in a series of high-profile conservatives to pressure Romney to open up about his finances. Perry, who has released his tax returns dating back to 1992, said anyone running for office should make public as much personal information as possible to help voters decide.
The conservative National Review magazine urged Romney to release additional tax returns even though it agreed with him that the Obama campaign wanted the returns for a "fishing expedition."
"By drawing out the argument over the returns, Romney is playing into the president's hands," the magazine said in an online editorial. "He should release them, respond to any attacks they bring, and move on."
Romney spokesman Kevin Madden said Romney will not bow to the pressure.
"The governor has gone above and beyond what's required for disclosure," Madden said. "The situation remains the same."
At the same time, Romney's campaign was forced to apologize for a supporter's statement that questioned Obama's patriotism, underscoring the political risks associated with the newfound aggression.
In a conference call arranged by the Romney campaign, former New Hampshire Gov. John H. Sununu told reporters he wished Obama "would learn how to be an American."
He later apologized for the remark.
"I made a mistake. I shouldn't have used those words. And I apologize for using those words," he told CNN. "But I don't apologize for the idea that this president has demonstrated that he does not understand how jobs are created in America."