What the ads don't mention — and what the Democratic congressman doesn't bring up on the campaign trail — is that last year he backed a measure that would have denied federal abortion funding even in cases of rape and incest.
Donnelly explains that while he opposes abortion he didn't initially realize the bill would have gone that far, yet the issue has made it difficult for him to capitalize on Republican Richard Mourdock's comment in a televised debate that pregnancy resulting from rape is something "God intended."
The abortion policy similarities between the two candidates and an electorate with deeply rooted social conservative beliefs have muted the impact of Mourdock's words in Indiana.
By comparison, Republicans quickly withdrew money and support from Missouri GOP Senate candidate Todd Akin after his controversial comment on abortion, and Democratic incumbent Claire McCaskill — an abortion rights supporter — surged in the polls. Akin's statement went further than Mourdock by saying that women's bodies have the ability to reject pregnancies in the case of a "legitimate rape."
Because Donnelly has campaigned carefully as a consensus-builder, the refocus of the race on abortion threatens to not just fail to help him but alienate voters who rallied to his cause because they view his policies as less-divisive.
Although many Democrats had hoped Mourdock's comment would be the October surprise needed to push Donnelly to victory, Donnelly instead has been forced to re-explain why he initially supported a measure that would have effectively created a separate class of "forcible rape."
"I said in February of 2011, 'Look, I want to prevent federal funds from being used for abortion-related services, but unless this language is taken out, I cannot vote for it,'" Donnelly said Tuesday while visiting a senior housing complex in Indianapolis. "I've been very clear that I'm a pro-life candidate. But this isn't about pro-life. This is about very hurtful remarks that are hurtful to women, to survivors of rape and to their families."
Immediately after the debate, Donnelly joined a chorus of Democrats and even some Republicans, including presidential contender Mitt Romney and Rep. Mike Pence, who's running for governor, in denouncing Mourdock's comments.
But Donnelly took few questions last week at a press conference he called the day after Mourdock's comments. And he quickly turned over the sharp rhetoric to surrogates such as the state's former Democratic Party chairwoman, allowing her to throw more haymakers while he got back to painting himself as a moderate.
A new ad by a Democratic-aligned super PAC ties Pence to Mourdock on the basis of the congressman's support for the legislation, but leaves out Donnelly's support for the same measure. And the Donnelly campaign began airing a new commercial this week hitting Mourdock for his comments, while again making no mention of his support for the legislation.
The strategy is one Democrats have employed throughout the campaign.
Beginning with Mourdock's GOP primary upset of veteran moderate U.S. Sen. Richard Lugar and continuing with comments in the days after the primary that the highlight of politics for him is "inflicting" his opinion on others, Democrats have been able to keep much of the campaign narrative focused away from Donnelly.
Donnelly's own campaign ads omit any reference to his party. Those efforts to stress bipartisanship have kept him afloat as a rare bright spot for Indiana Democrats, who lost two congressional seats and control of the state House in the last election.
The anti-abortion slant of Indiana's electorate is hardly in doubt. Gov. Mitch Daniels approved an effort last year to defund Planned Parenthood, and Pence has led the effort in Congress to cut support for the group. Both Donnelly and Democratic gubernatorial candidate John Gregg oppose abortions, except in limited cases.
Republicans who initially blasted Donnelly's support for the abortion bill have since tried to move away from Mourdock's abortion comments, returning to their main theme that Donnelly is a partisan Democrat who's supported many of President Barack Obama's controversial measures, such as the auto bailout and federal health care overhaul.
Mourdock's staff has griped to reporters that Donnelly is getting a free pass on his support for the forcible rape legislation.
Mourdock says his words during the debate were "twisted" by Democrats and others but said it's Donnelly's choice if he wants to crack open the abortion issue on the campaign trail.
"The fact that he's going to politicize that issue, I think, is a decision he has to make," Mourdock said. "I just saw, even as we were speaking, a quote up on the TV from the Wall Street Journal where they called it 'sleazy.' Certainly I think that's an apt description if he wants to politicize that issue, which is certainly not one that I tried to politicize."
Many voters say they understood what Mourdock meant when he made his comment about pregnancy. That doesn't mean they like it.
Sara Jacobs, 69, said she talked with Donnelly about Mourdock's comments during his visit to her senior living complex.
"He put not one, but both feet in his mouth," Jacobs said.
Amy Leonard, a South Bend mother of three, said she understood Mourdock was trying to say that all life is precious but disagrees with how the words came out. She plans to split her ticket, voting Republican for governor and Democrat in the Senate race.
"That is one topic I stay away from, is abortion. No matter what, you are going to make somebody mad. You can never give the right answer," she said.
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