It does this by pointing out that Pence was a co-sponsor of the Republican's "No Taxpayer Funding For Abortion Act", which the voice-over describes in hushed, indignant tones as "a bill that would have re-defined rape as 'forcible rape'," without mentioning that another co-sponsor of that bill was...
...fellow Congressman Joe Donnelly (D-IN), currently running against Mourdock for RINO Dick's old senate seat. As Slate puts it:
Oddly, the attack ad in question neglects to mention that Rust Belt Catholic Blue Dog Donnelly skipped down the aisle hand-in-hand with demonic conservative zealot Pence on this issue. Huh. Funny, that...And that vote is probably worth explaining. Like Rep. Bart Stupak, Donnelly initially refused to support the health care bill for fear that it would fund abortions. Stupak and Donnelly switched their votes when the president promised a mostly toothless executive order that reaffirmed the no-money-for-abortion language. Most of the Stupak caucus lost their elections in November. Donnelly survived, then co-sponsored the Republicans’ “No Taxpayer Funding for Abortion Act,” which (in initial drafts) changed a legal reference from “rape” to “forcible rape.”
So it should be Donnelly, not Mourdock, who’s squirming to explain his abortion stance. For a while he was, giving mushy answers about his stance on the Affordable Care Act’s contraception mandate. Then Mourdock effectively bailed him out, and Donnelly has benefited from third-party attacks on his opponent.