Romney is on record, however, as not opposing abortion in cases of rape and incest or if it will save the mother's life.
Polling shows social issues such as abortion represent perhaps Obama's best opportunity to draw support from Romney. Obama already holds a broad lead as the candidate more trusted to handle those social issues among Democrats and independents. The issue is one of Romney's biggest vulnerabilities among moderate and liberal Republicans.
Obama also sought to chip away at Romney's trustworthiness, taking fresh shots at Romney's refusal to release years of tax returns for public inspection. He said that position was indicative of a candidate who has a "lack of willingness to take responsibility for what this job entails."
Yet it is the economy that has driven this election and has dominated Obama's message of a middle-class revival.
"We aren't where we need to be. Everybody agrees with that," said Obama, who inherited an economy in free fall and now bears responsibility for a recovery that remains weak. "But Gov. Romney's policies would make things worse for middle-class families and offer no prospect for long-term opportunity for those striving to get into the middle class," the president said.
A Romney spokesman, Ryan Williams, jumped on Obama's account in the interview that the economy clearly needs to get better. "Mitt Romney and Paul Ryan agree," Williams said. "The American people know they aren't better off than they were four years ago."
Obama holds a decisive advantage over Romney when Americans are asked who better understands their daily woes. Yet nearly two-thirds of people in a new AP-GfK poll say the economy is in poor shape, and 60 percent say the country is headed in the wrong direction.
Obama expressed confidence that even voters whose lives have not improved during his term will stick with him as they assess the two candidates.
"If they saw Gov. Romney offering serious proposals that offered some sort of concrete ways in which middle-class families would be helped, then I could understand them thinking about that choice," Obama said. "But that's not what's happening."
And therein lies the central case that Obama made in the interview, as he has made for months, and as he will again at his own party's convention in Charlotte, N.C., in early September.
Obama said he is the candidate whose policies have historically helped the middle class on issues that people care about and that shape the economy — education, manufacturing, science and research, Medicare, debt reduction, tax rates, health care, consumer protection, college aid, energy.
Williams, the Romney spokesman, responded that Obama has piled up national debt and presided over high unemployment. "Too many middle-class families are going to sleep each night worried," he said. "This may be the best President Obama can do, but it's not the best America can do."
The moment that could finally shake up a close race could come in the three debates Obama and Romney hold in October. The president said Romney could run into trouble because of arguments that are not backed up by facts, citing a widely debunked television ad campaign in which Romney accuses Obama of gutting the work requirement in the federal welfare law.
"It will be a little tougher to defend face-to-face," Obama said.
Obama's view of a different second-term dynamic in Washington, even if both he and House Republicans retain power, seems a stretch given the stalemated politics of a divided government. He said two changes — the facts that "the American people will have voted," and that Republicans will no longer need to be focused on beating him — could lead to better conditions for deal-making.
If Republicans are willing, Obama said, "I'm prepared to make a whole range of compromises" that could even rankle his own party. But he did not get specific.
The 25-minute interview, conducted in the library of the White House residence, was part of a multi-faceted campaign by Obama's team to snag some of the spotlight during Romney's big week. Obama denied the notion, widely if quietly held in political circles, that the fiercely competitive president is also driven to beat Romney because he does not hold him in high regard.