A Bruising Time, Again, for Mitt Romney Back in January, Mitt Romney faced a series of politically searing moments, any one of which had the potential to bring a swift end to his second bid for the White House. His Republican rivals tore into his role as the founder of Bain Capital, calling him a vulture capitalist. They demanded that Mr. Romney release his tax returns, raising the question of whether Mr. Romney had used overseas tax havens that allow the mega-rich to dodge what they really owe. And they jumped on Mr. Romney's gaffes, twisting his own words - "I'm not concerned about the very poor" - to score political points in the bruising nominating fight. At the time, aides to Mr. Romney and veteran political observers found a silver lining: If he could survive the attacks and become the party's nominee, the thinking went, he would be stronger for it all. The positive thinking was built on two premises: First, that any controversy that flared up in January would become old news by summertime, making it less likely that President Obama and his Democratic allies could make hay of it in the general election. And second, that Mr. Romney would be forced to find good, strong answers to the criticisms. There would be nothing left, they predicted, that could catch Mr. Romney off guard or unprepared when he faced Mr. Obama's disciplined and aggressive campaign. In a Times article in mid-January, Mr. Romney's advisers indicated they "believe that this criticism could help inoculate him against similar Democratic-led attacks if he becomes the Republican nominee, since the story of Bain Capital could be well-worn by then." It hasn't quite worked out that way. The issues of Mr. Romney's taxes, his time at Bain Capital and his string of verbal gaffes during the primaries have become the centerpieces of the Democratic attempt to define him as rich, out of touch and unacceptable. And Mr. Romney's campaign has made surprisingly little progress since the winter in finding effective responses to the attacks. This week, Mr. Obama's campaign and his Democratic allies began an all-out effort to revive the questions about Mr. Romney's personal wealth and his refusal to make more than one full year of tax returns public. A web video released by Mr. Obama's campaign uses the words of Senator Charles E. Grassley, a Republican from Iowa, to cut to the heart of the issue. In response, Mr. Romney and his campaign have said what he said back in January - that he has done nothing wrong and has paid all the taxes he owed. And as he did during the primaries, Mr. Romney has sought to shift the focus back to his opponent, in this case by accusing Mr. Obama of trying to keep documents secret in the Congressional investigation of gun-running on the Mexican border. "I'm glad he wants to talk about transparency," Mr. Romney said on Fox News, "because he has used executive privilege to prevent the American people from knowing the truth of what happened with the Fast and Furious program." But it is the Democratic attacks on Mr. Romney that have come fast and furious in the last several months. In most cases, they are revivals of the very issues that Mr. Romney's strategists thought they might have put to rest in the primary. Polling shows the race between Mr. Romney and Mr. Obama to be virtually tied. But buoyed by surveys suggesting the attacks are working, Mr. Obama and his allies are continuing to question Mr. Romney's work at Bain Capital. The fact that Newt Gingrich and Gov. Rick Perry of Texas seized on the same issue in January and February hardly seems to have lessened its impact. In part, that's because Mr. Obama's team has found a new way to frame the subject. After initially duplicating the corporate raider theme from the Republicans, Mr. Obama's campaign has more recently used the Bain years to accuse Mr. Romney of investing in companies that moved jobs overseas. That new angle - and millions of dollars to publicize the issue with television commercials - breathed new life into the Bain attacks. And as the Times's Jeff Zeleny and Ashley Parker report Thursday, Mr. Romney's responses have caused some handwringing among some members of his party. Mr. Romney's discipline as a candidate has improved in recent months. Since becoming the presumptive Republican nominee, he has made fewer of the verbal gaffes that seemed to blunt his momentum at every turn during the nominating fight. But even those moments are not buried in the past. In one interview in early February, Mr. Romney said that he was "not concerned with the very poor." In context, he was arguing for a focus on the middle class, not the rich or the poor. But his Republican rivals pounced. Now, that dormant phrase is back. A new Spanish-language television ad by a pro-Obama "Super PAC" and a union group shows Mr. Romney uttering that sentence, followed by a man speaking in Spanish. "He's a person without feelings who doesn't care about people whether they be Hispanic, Latino, white, who are below him," the person says. Other verbal miscues - including when Mr. Romney said that corporations are people, too - also remain potent rhetorical weapons that Democrats continue to use on the campaign trail. Some public polling suggests that the attacks on Mr. Romney's Bain experience are working to make him less likable among important groups of swing voters. But that evidence is hardly overwhelming, and the Republican candidate still has plenty of time to find ways to respond effectively. But there is little doubt now that the "glass half-full" attitude among some of Mr. Romney's supporters six months ago has faded. The attacks by Mr. Gingrich, Mr. Perry and the other Republican candidates did not inoculate Mr. Romney. And the fact that his campaign is still searching for the best way to respond suggests that all the practice in the world during months of intra-party squabbles did not help that much. If Mr. Romney were asked, it's likely he would have preferred not to go through that in the first place.