Mitt Romney still has a chance to define himself for voters at several key junctures left in this campaign, in spite of the Obama campaign’s furious efforts to paint the presumptive GOP nominee essentially as a corporate raider and out-of-touch millionaire.

President Obama’s team has poured millions into advertising that voices suspicions about Romney’s personal wealth and his time at Bain Capital in hopes of priming voters’ perceptions of the former Massachusetts governor. In turn, the Romney campaign has been knocked off-message in recent weeks by questions surrounding his departure from Bain and demands that he release additional years of tax returns.

Evan Vucci / AP

Republican presidential candidate Mitt Romney leaves a fundraiser July 16 in Baton Rouge, La.

“It's incredibly disciplined,” said Bob Shrum, the longtime Democratic consultant, of the Obama campaign’s efforts. “They obviously knew what they were doing coming out of the primary. They obviously tested these tactics in focus groups and polling.”

But if the Romney campaign is sweating these attacks, the public would never know it. The Boston-based team hasn’t budged in the face of demands – even from conservatives – that Romney release more tax returns. And they’ve waved off questions about Romney’s retirement from Bain as a distraction.

GOP frets about swing state toll on Romney from Bain attacks

There is evidence the Obama campaign’s attacks have taken a toll on Romney among voters in swing states, especially ones with heightened scrutiny of outsourcing. But Republicans are quick to note that Romney still has ample opportunities to introduce himself to voters – on his own terms.

“Mitt Romney, when you look at the race, there’s nine or 10 really consequential hours left in the campaign,” said Steve Schmidt, a senior adviser to Arizona Sen. John McCain’s 2008 presidential campaign.

In short, Republicans believe that few voters have yet to tune in fully to the campaign, and that Romney has several opportunities to reach voters who might be less familiar with his background and record.

There have been indications that the first opportunity, Romney’s selection of a running mate, could come as early as this week. Senior adviser Eric Fehrnstrom on Monday wouldn’t rule out a pick this week for reporters, and the Romney campaign continued to stoke speculation Tuesday morning by announcing senior staff for the impending VP pick.

First Thoughts: Don't bet on an early VP pick

And Romney will have other opportunities to make his case in an unfettered medium to voters who are thought to start paying more close attention to the campaign at the end of summer. The Republican National Convention next month in Tampa, if executed well, could prove a chance to lionize Romney and the GOP ticket. And the three scheduled presidential debates this fall between Obama and Romney will prove a pivotal opportunity for voters to size up the two candidates versus each other.

Moreover, there are other inflection points that might allow Romney to seize control of the media narrative – among them his foreign tour later this month that will take him to the Summer Olympics in London and, afterward, to Israel.

“Voters by definition don’t lock in until the entirety of the process plays out,” said Schmidt. “We’re about to enter a phase of the campaign where there are a number of events that are watched by tens of millions of people that could affect the trajectory of the race.”

RELATED: Is Romney too focused on the economy?

But there are potential liabilities associated with simply trying to wait out the summertime bickering between the campaigns.

Case-in-point: the 2004 presidential campaign, when withering attacks from the outside conservative group “Swift Boat Veterans for Truth” took aim at Democratic nominee John Kerry’s military record.

Those attacks, said Shrum, didn’t necessarily convince voters that Kerry was unqualified to serve as commander in chief, but he said they did “disrupt our campaign for two to three weeks.”

Mark McKinnon, a former political adviser to President George W. Bush’s campaign, said the similarities between the 2004 Republican campaign and Obama’s re-election effort were “spooky.”

Among the most striking similarities, he said, are Bush and Obama’s shared effort to make the race into a choice between the two candidates rather than a referendum on the incumbent’s first term – an important strategy given the potential vulnerabilities Bush had on foreign policy and Obama suffers on the economy.

And Bush, like Obama, also spent early and heavily to frame the race.

Some conservatives have even openly mentioned the possibility that Romney might be “Swift Boated” in reference to the attacks he now faces from the Obama campaign. It’s part of the reason that the right has begun to clamor for a more aggressive response by Romney to the president’s attacks.

If he loses this fall, the former Massachusetts governor might find himself the victim of the second-guessing that inevitably follows a party’s losing electoral effort. And if he wins, Romney might be the beneficiary of the same praise heaped on the Obama campaign for its supposedly disciplined and unrattled operation.

“That’s how you win campaigns,” said Shrum. “Having a good strategy, consistently executed is much better than constantly searching for a perfect strategy and intermittently executing it.”

Republicans are beginning to look with trepidation at the Obama campaign’s all-out effort to turn Mitt Romney’s business experience into a political liability, particularly in corners of the country that could decide the November election.

President Barack Obama’s team has relentlessly blanketed the airwaves in specific states – like Ohio, Michigan, Wisconsin and Pennsylvania – looking to prime swing voters who might be susceptible to fret over suggestions that Romney had contributed to the growth in outsourcing jobs overseas during his time at Bain Capital. 

Republicans, including Romney, dismiss the ads as a distortion and a distraction from the president’s own record on the economy. But some in the GOP worry these attacks could take their toll and prove effective unless action is taken.

Charles Dharapak / AP

Republican presidential candidate Mitt Romney's business experience may become a political liability in the November election.

“As a baseless charge, this is something that can potentially be dispelled,” said former Pennsylvania Rep. Phil English, a Republican who represented the blue collar town of Erie. “But if the Romney campaign does not aggressively engage it and address it directly, I think they could suffer, potentially, a significant loss of voters.”

The Obama campaign’s line of attack versus Romney found its origin in the Republican primary, when Romney’s opponents charged him with perpetuating “vulture capitalism” during his time at Bain Capital. They pushed him to release years’ worth of tax returns, which the Obama campaign is now demanding as well.

Video: First Read Minute: Two key battlegrounds

Though the Obama campaign endured a measure of friendly fire from Democrats (who questioned the wisdom of attacking Romney’s private sector career) since it revived these attacks for the general election campaign, they largely haven’t let up in their scrutiny of Romney’s Bain record.

"Outsourcing versus insourcing. It matters," one of the Obama campaign's ads says, flashing pictures of Romney and Obama, respectively.

They were handed an additional piece of ammunition by a Washington Post article labeling Bain a “pioneer” in the practice of outsourcing while Romney was in charge. The Obama campaign has spent millions on advertising trumpeting that claim, disregarding the nonpartisan group FactCheck.org’s research that the underlying assertion was untrue.

“This is not dissimilar to the stuff Sherrod Brown ran against me in '06, but the difference is the climate,” said Mike DeWine, the former Republican senator from Ohio who lost his bid for re-election in the 2006 Democratic wave election.

DeWine, who now serves as Ohio’s attorney general, switched his support from Romney to former Pennsylvania Sen. Rick Santorum during the GOP presidential primary, partly because he felt that Santorum would do a better job connecting with middle class voters.

“I don't know who's going to win, but this year is not '06,” he continued. “It remains to be seen whether they work in '12 or not.”

There are signs, though, that the Obama campaign’s attacks have had an effect. Forty-two percent of registered voters in a Washington Post/ABC News poll released Tuesday said they think Romney’s work as a corporate investor did more to cut jobs, versus 36 percent who said it was more directed toward creating jobs.

Recommended: First Thoughts: The importance of Colorado and Iowa

Strikingly, the poll also found that twice as many voters in swing states said that Romney’s business career was a major reason to oppose him than those who said it’s a major reason to support.

Republicans originally found success in using this line of attack versus Romney as recently as this year. Former House Speaker Newt Gingrich and Texas Gov. Rick Perry pummeled Romney over his business record and personal wealth leading into the South Carolina primary, contributing, in part, to Romney’s loss in that contest.

Katon Dawson, a longtime figure in South Carolina Republican politics who spearheaded Perry’s campaign there, said he didn’t expect Obama to find much success in using this tactic.

“If it didn't stick in the Republican primary, it's not going to work in the general,” he said. “There's no way they're going to blame Mitt Romney for a member of their family being out of work.”

English said he distinguished between the attacks on Romney’s wealth and personal background from the Obama campaign’s claims about outsourcing. The latter, he said, had the potential to be much more potent in pivotal Midwestern states.

“I think you have to answer ads with ads,” he said. “There’s a tendency by Republicans to assume the truth will catch up. I think there is a naive quality to Republican thinking that they don't have to answer these charges.”

“I think the rule in politics is to be on offense, and he’s got to be on offense, not defense,” DeWine said.

Republicans are quick to note, too, that Romney has plenty of time to do just that. They praise Romney’s organization and the tenacity of the candidate himself. DeWine noted that most Ohioans have been more tuned into the Fourth of July and recent weather than the presidential election. And Dawson said that conservatives are more mobilized behind Romney than ever, after the Supreme Court issued its decision upholding the president’s health care reform law.

But the president’s own bus tour last week provided some clues about where Team Obama thinks the election could be won or lost. The stops through northern Ohio and western Pennsylvania cut through many of the areas where economic anxiety is near its peak; these areas were among the hardest hit by the downturn in manufacturing, and the loss of jobs to overseas labor.

“They're going after the swing voter,” Dawson said of the Obama campaign’s strategy. “This game is going to be played out among 9-12 million people in the places that put Republicans back in charge in 2010.”

That sentiment underscores a reality that the Obama campaign has tailored its attacks against Romney to both play to voters they desperately need to win, while also exploiting what they think to be a vulnerability of Romney’s.

“Every candidate has strengths and weaknesses, and if it were another candidate, I guess Democrats would be doing something else,” said DeWine.

The Obama campaign's assault on Mitt Romney's private sector career is meant to accomplish two goals: tarnish the cornerstone of the presumptive GOP nominee’s political biography, and play into middle class voters' economic anxieties over the actions of large financial institutions.

The president's re-election team sent notice Monday morning that its new ad, which took aim at Bain Capital's involvement at a Kansas City steel plant, was only the first in a sustained wave of attacks on the company Romney co-founded.

David Karp / AP

President Barack Obama arrives at JFK International Airport May 14 in New York on his way to deliver the commencement address at Barnard College in New York City.

"Most Americans know that, even in the real world, when you bankrupt a company, you don't walk away with millions of dollars for yourself and others while workers are left holding the bag," said Stephanie Cutter, the deputy campaign manager for the Obama team, in a conference call Monday morning.

"That's simply wrong, especially if you're using those lessons and values learned from that experience as the central premise of your campaign for president. Romney didn't care about rewarding hard work and responsibility, he didn't care about everyone playing by the same set of rules; he cared about making money for him and his partners at all costs," she said.

RELATED: Obama campaign criticizes Romney's 'economic values'

The Romney team cried foul in response, accusing the president of diverting attention from the anemic performance of the economy. “We welcome the Obama campaign’s attempt to pivot back to jobs and a discussion of their failed record.  Mitt Romney helped create more jobs in his private sector experience and more jobs as Governor of Massachusetts than President Obama has for the entire nation,” said Andrea Saul, Romney’s press secretary.

Later in the day, the Romney campaign released its own web video touting Steel Dynamics, one of the success stories during Romney's time at Bain, as a countervailing example.

(Bain, in its own statement this afternoon, emphasized its neutrality in the election and decried how its "exemplary 28-year record will be distorted and complex business situations will be portrayed in a simplistic way.")

Nonetheless, the Obama campaign’s new plan to conduct a sustained assault on Romney’s record represents an effort to turn what’s regarded as one of the Republican’s greatest strengths – his economic expertise – into a liability.

As NBC Politics previously explored, Romney has an advantage versus Obama on the economy, though not by as wide of a margin as his campaign might hope. Moreover, the data in last month’s NBC News/Wall Street Journal poll suggested that voters didn’t expect the economy to perform much better in a Romney administration vs. a second term from Obama. In short, neutralizing Romney’s advantage on the economy would throw the election to other factors, and Obama holds the advantage on many of those.

Romney sells economic acumen - are voters buying?

But the Obama campaign’s attack also plays into broader themes of fairness and equality on which the president has staked his re-election effort.

"We have to move forward, to the future we imagined in 2008, where everyone gets a fair shot, and everyone does their fair share, and everyone plays by the same rules," he said earlier this month at his campaign launch in Columbus. "That’s the choice in this election, and that’s why I’m running for a second term as president of the United States."

An early April Washington Post/ABC News poll suggested that this message, versus a more generic Republican argument about overregulation, might have more political traction. Fifty-two percent of Americans in that poll said they viewed unfairness in the economy that favors the wealthy as a bigger problem than overregulation, named by 37 percent of Americans as a bigger problem.

That message is necessitated partly by the sluggish growth in employment in recent months; while the economy is improving, the rate at which hiring has improved makes it more difficult for Obama and Democrats downballot to run on the economy.

First Thoughts: Bain returns

But the Obama campaign is betting that diminished faith in major institutions – and outright skepticism toward Wall Street and the rest of the financial sector – might be enough to stave off Romney’s attacks, especially if they can link the former buyout guru to the excesses of corporate titans.

Obama himself noted that banks and other financial behemoths hadn’t been “model corporate citizens” in his commencement address Monday at Barnard.

There are plenty of examples toward which Obama and his party can point, and already, some of the party’s candidates have gotten the memo.

Elizabeth Warren, the Democratic Senate candidate in Massachusetts who had earned plaudits from liberals for her efforts to rein in Wall Street, seized on news that J.P. Morgan had lost $2 billion in a hedging scheme to call on CEO Jamie Dimon to resign his position as director of the New York Federal Reserve Board.

“There’s been a guerilla war out there in which the largest financial institutions have been doing everything they can to make sure that financial regulations don’t get put in place, and if they do get put in place, that they’re loaded with loopholes, and not very effective,” she said Monday on CNN.

CHARLESTON, S.C. – The audience at a presidential forum here Saturday booed Newt Gingrich for criticizing Mitt Romney’s record at Bain Capital after Mike Huckabee, the host, told the crowd that candidates would not be allowed to attack each other.

Before the five candidates (Ron Paul was not there) came out one by one for approximately 12 minutes of audience questions, Huckabee explained that they were “not to mention, and not to attack the other candidates.” (The audience, prompted at first by the Huckabee show’s executive producer, clapped and cheered at the directive.)

Gingrich, the third candidate to speak, responded to question about how he could “defend the vilification of companies that are willing to put capital at risk in order to save failing companies” -- a reference to attacks by Gingrich and his super PAC over Romney’s tenure at Bain Capital.

Pushing back on the claim of “vilification,” Gingrich said, “I haven’t done that.”

He began to say he would be visiting the city of Georgetown, which used to be home to a steel mill whose parent company was bought out by Bain in 1993 and went bankrupt in 2001 with more than $500 million in debt according to a Myrtle Beach Sun News account.

“Georgetown has a steel mill. Which was closed. Capital wasn’t put at risk; capital was drained out of that company,” Gingrich said. “Governor Romney ran saying he created 100 thousand jobs in the private sector…”

The audience started booing Gingrich after he said, “Governor Romney.”

Huckabee interrupted Gingrich, saying, “Mr. Speaker, we said we will not allow negative…”

Then Gingrich, retooling, continued, “I’m just trying to answer his question. So let me say it differently.”

“OK,” Huckabee replied.

“I believe that it’s fair to ask the records be clear and that people reveal what happened,” Gingrich said. “But I think to ask questions about a particular company is not the same as attacking capitalism and I don’t see how you can expect us to have a presidential campaign in which an entire sector is avoided."

Several audience members at the forum told NBC News they were displeased at Gingrich’s singling Romney out.

“I think Gingrich lost my respect,” said Janice Shumpert, 57, of West Ashley, who said she was leaning towards Rick Santorum. “It was a bad moment for him. I’m not saying he can’t recover but at this point, I wouldn’t vote for him”

Randy Hinson, 56, of Charleston, said the booing was “appropriate” because “that wasn’t the format.”

“Gingrich actually ruled himself out today for me,” Hinson said. “I guess Romney was at the top for me; I wanted Gingrich, and Gingrich kind of talked himself out of it today.”

Pat Neumann, 58, of Edisto Island, who said she favored Perry, noted the enthusiastic response Huckabee received when he said the forum was to be devoid of negativity.

“We weren’t going to put up with that,” she said of candidate-on-candidate aggression. “It’s going to happen because unfortunately negative campaigning works, and they know it. But people just weren’t going to put up with it today.”

WEST COLUMBIA, SC -- Presidential hopeful Rick Santorum on Wednesday hit his Republican rivals for their critiques of frontrunner Mitt Romney's record at Bain Capital, calling their criticisms of the former Massachusetts governor an attack on capitalism. 

Former House Speaker Newt Gingrich and Texas Gov. Rick Perry have used Romney's time at the investment firm to portray him as a business tycoon who fired scores of workers for his own profit.  But Santorum likened such attacks to what he called the anti-capitalism rhetoric President Obama has used to attack America's most financially successful corporate leaders.  Rhetoric, Santorum says, that has stalled the economy and put the country's free market system into question.

"It’s this hostile rhetoric, which unfortunately - I don't want to stand here and be a defender of Mitt Romney, but unfortunately even some in our party now, even some running for president will engage in with respect to capitalism," Santorum said to a town hall of nearly 200 people. "It is bad enough for Barack Obama to blame folks in business for causing problems in this country. It’s one other thing for Republicans to join him."

While others seeking the GOP nomination see Romney's time at Bain and recent comments that he enjoys the ability to fire people as an opening for political attacks, the former Pennsylvania senator has not piled on.  Even when prodded by reporters to take a shot, Santorum instead has only said he believes in the economic model that allows people to be successful.

However, that does not mean Santorum has shied away from taking jabs at Romney.  The candidate trying to portray himself as the only true conservative in the race has elected to use Romney's record as a governor, not a businessman, to go on the offensive.

"The other side is going to look at my record and look at Gov. Romney's record on health care and say, 'You want to attack me on health care?  Who are you to attack me on something that I used your plan to build my health care method?'" said Santorum.  "He's taking away the biggest issue that we have in this election."

The former Pennsylvania senator arrived in South Carolina on Wednesday coming off a fifth place finish in the New Hampshire primary, where he told those here not to look at his ultimate finish, but how dramatically he improved in his poll numbers since last month.