WASHINGTON (CNN) -- A campaign flub by a Republican Senate candidate shifted the political focus Monday to abortion and women's rights, as certain GOP nominee Mitt Romney and his conservative running mate faced a town hall-style meeting in New Hampshire.
U.S. Rep. Todd Akin, R-Missouri, said Sunday he misspoke when he said in an earlier interview that "legitimate rape" rarely resulted in pregnancy. Akin also expressed opposition to abortion in cases of rape.
The comment by Akin, who won Missouri's Republican primary to take on incumbent Democratic Sen. Claire McCaskill in November, drew immediate criticism from Democrats and some Republicans.
In Massachusetts, U.S. Sen. Scott Brown called for Akin to drop out of the Missouri Senate race because of the "outrageous, inappropriate and wrong" comments.
"There is no place in our public discourse for this type of offensive thinking," said Brown, a moderate Republican in a tough re-election battle against Democrat Elizabeth Warren. "Not only should he apologize, but I believe Rep. Akin's statement was so far out of bounds that he should resign the nomination for U.S. Senate in Missouri."
The Akin statement has forced the Romney campaign to distance itself from the GOP candidate in a key race, and also declare a definitive stance on one of the most volatile political issues of the day.
A Romney spokeswoman issued a statement Sunday night that said the former Massachusetts governor and his running mate -- Rep. Paul Ryan of Wisconsin -- differed with Akin on the matter.
"Governor Romney and Congressman Ryan disagree with Mr. Akin's statement, and a Romney-Ryan administration would not oppose abortion in instances of rape," Romney campaign spokeswoman Amanda Henneberg wrote.
The issue is particularly sensitive for Ryan, a devout Catholic and staunch anti-abortion politician who has previously expressed opposition to abortion in all cases except when the life of the mother is endangered.
A Romney-Ryan campaign official, speaking on condition of not being identified, confirmed to CNN that Ryan's personal view opposes abortion in the case of rape. The campaign official said Ryan's stance differed with Romney's view, which was described in the statement Sunday and is the formal position of the GOP presidential ticket.
Democrats immediately challenged the Romney-Ryan team on the issue.
"They've been trying to distance themselves from it -- but Congressman Ryan has already partnered with Akin on a whole host of issues that restrict women's ability to make their own health care decisions," said a statement by Rep. Debbie Wasserman Schultz, the chairwoman of the Democratic National Committee. "This kind of 'leadership' is dangerously wrong for women."
Meanwhile, Republican colleagues also criticized Akin.
"As a pro-life conservative, a husband, and a father of two young women, I find Representative Akin's remarks to be offensive and reprehensible," said Rep. Denny Rehberg, a Republican candidate for a Montana seat in the U.S. Senate this year. "There is no such thing as a 'legitimate rape.' I condemn Representative Akin's statements in the strongest possible terms."
A spokesman for the National Republican Senatorial Campaign, Brian Walsh, said Akin "did the right thing by quickly correcting the record and acknowledging that he misspoke."
The abortion focus comes in a week when the Romney team wanted to sharpen its focus on economic issues in the run-up to the Republican National Convention, which begins on August 27 in Tampa, Florida.
Now, Romney and Ryan will face questions about the volatile abortion issue and women's rights, giving President Barack Obama and Democrats an opportunity to further strengthen their advantage with women voters -- a demographic that already favors them, according to the polls.
Akin, answering a question from KTVI about whether or not abortion should be legal in the case of rape, explained his opposition by citing unnamed bodily responses that he said prevented pregnancy.
"First of all, from what I understand from doctors, that's really rare," Akin said of rape-induced pregnancy. A clip of the interview was posted online by the liberal super PAC American Bridge.
"If it's a legitimate rape, the female body has ways to try to shut that whole thing down," Akin continued. He did not provide an explanation for what constituted "legitimate rape."
He added: "But let's assume that maybe that didn't work or something. You know I think there should be some punishment, but the punishment ought to be on the rapist and not attacking the child."
In a statement Sunday, Akin wrote that he misspoke in the interview. He maintained his opposition to abortion for victims of rape.
"In reviewing my off-the-cuff remarks, it's clear that I misspoke in this interview and it does not reflect the deep empathy I hold for the thousands of women who are raped and abused every year," he wrote. "Those who perpetrate these crimes are the lowest of the low in our society and their victims will have no stronger advocate in the Senate to help ensure they have the justice they deserve."
Akin continued that he recognized that abortion, "and particularly in the case of rape, is a very emotionally charged issue."
"But I believe deeply in the protection of all life and I do not believe that harming another innocent victim is the right course of action," he said. "I also recognize that there are those who, like my opponent, support abortion and I understand I may not have their support in this election."
Statistics on pregnancies that result from rape are difficult to produce, since rape is a crime that often goes unreported.
The Rape, Abuse & Incest National Network, along with Planned Parenthood, each estimate that 5% of rapes lead to pregnancy. A 1996 study from the Medical University of South Carolina found the same percentage, adding that 32,101 pregnancies occurred annually from rape.
Akin, a six-term U.S. congressman, touted his socially conservative values on the primary campaign trail.
He opposes abortion in all circumstances and has said he also opposes the morning after pill, which he equates to abortion.
McCaskill responded almost immediately to her opponent's comments Sunday, writing on Twitter: "As a woman & former prosecutor who handled 100s of rape cases, I'm stunned by Rep Akin's comments about victims this AM."
She later released a statement condemning her rival as "ignorant about the emotional and physical trauma brought on by rape."
"The ideas that Todd Akin has expressed about the serious crime of rape and the impact on its victims are offensive," she continued. McCaskill's website also splashed Akin's comments across the homepage, and included a link where supporters could donate money to McCaskill's campaign.
Republicans consider McCaskill, first elected in 2006, highly vulnerable in her bid for a second term. Ahead of the GOP primary, a Mason-Dixon poll showed the senator falling behind Akin and the two other main GOP primary competitors in hypothetical match-ups among registered Missouri voters.
Akin was one of the first members of Congress to join the Tea Party Caucus in 2010 and has easily won re-election in recent years. The lawmaker has raised a notable $2.2 million this cycle, as of July 18.
Before the new controversy, the top nonpartisan political handicappers had rated the Missouri race a "toss-up."
CNN's Paul Steinhauser, Kevin Liptak and Ashley Killough contributed to this report.