Similarly, Schilling is trying to win reelection in a Democratic district against a female candidate.
National Republican Senatorial Committee (NRSC) Chairman John Cornyn (Texas) characterized the comments as an expression of Mourdock's previously well established belief that life begins at conception.
"Richard and I, along with millions of Americans — including even Joe Donnelly — believe that life is a gift from God. To try and construe his words as anything other than a restatement of that belief is irresponsible and ridiculous," Cornyn said in a statement.
Mourdock clarified later that his point was “God creates life."
"God does not want rape, and by no means was I suggesting that he does," he said. "Rape is a horrible thing, and for anyone to twist my words otherwise is absurd and sick.”
Democrats including President Obama and Democratic National Committee Chairwoman Debbie Wasserman Schultz (D-Fla.), have called Mourdock's original remark offensive to women, and the Obama campaign is seeking to closely align presidential contender Mitt Romney's position on abortion rights to Mourdock's. The GOP nominee has endorsed Mourdock and the two appear together in an ad.
The Romney campaign said it stands by Mourdock, as well, although the specifics of his policy position do not match those of the GOP nominee. Romney believes in exceptions for rape, incest and the life of the mother, while Mourdock on Tuesday night was explaining why he only believes abortion should be allowed in cases where the mother's life is at risk.
Mourdock said Wednesday he cannot apologize for "speaking from my heart, from the deepest level of my faith" on Tuesday, and said Democrats have "twisted" the meaning of what he said.
—Cameron Joseph contributed to this report.