"I don't know how these guys come up with these ideas," Obama said in an appearance on the "The Tonight Show with Jay Leno" Wednesday. "Let me make a very simple proposition -- rape is rape. It is a crime. And so these various distinctions about rape don't make too much sense to me, don't make any sense to me."
Obama, who supports abortion rights, has emphasized the issue in his bid for a second term, warning women some Republicans would like to see abortion outlawed in all cases.
"This is exactly why you don't want a bunch of politicians, mostly male, making decisions about women's healthcare decisions," Obama said on the program.
"Women are capable of making these decisions in consultation with their partners, with their doctors, and for politicians to want to intrude in this stuff, oftentimes without any information, is a huge problem. And this is obviously a part of what's at stake in this election."
Mourdock, supported by the Tea Party movement, said during a Tuesday debate life conceived by rape "is something that God intended to happen" and must be protected from abortion.
He said Wednesday he was sorry if he offended anyone with his comment and accused Democrats of distorting his comments for political gain.
"For those who want to kind of twist the comments and use them for partisan political gain, I think that's what's wrong with Washington these days," said the candidate who defeated longtime incumbent Sen. Richard Lugar in a May primary.
"I spoke from my heart, I spoke with my principle, I spoke from my faith," said Mourdock, a Roman Catholic. "And if others want to somehow turn those words and use them against me, again, that's what's wrong with Washington today."
His initial comment, during a debate with Democratic Senate candidate Rep. Joe Donnelly, was: "I've struggled with it myself for a long time, but I came to realize that life is that gift from God. And even when life begins in that horrible situation of rape, that it is something that God intended to happen."
In his follow-up comments, Mourdock said his point was, "God creates life."
"God does not want rape, and by no means was I suggesting that he does," Mourdock said.
National Republican Senatorial Committee Chairman Sen. John Cornyn, R-Texas, said Wednesday his committee would still support Mourdock.
"Richard and I, along with millions of Americans -- including even Joe Donnelly -- believe that life is a gift from God," Cornyn said in a statement.
"To try and construe his words as anything other than a restatement of that belief is irresponsible and ridiculous," he said.
The committee's decision to stand by Mourdock contrasts with its initial decision to drop support for Senate candidate Todd Akin of Missouri after he said in August pregnancies couldn't result from "legitimate rape." The NRSC later indicated it was reconsidering that position.
The campaign of Republican presidential nominee Mitt Romney said in a statement the former Massachusetts governor "disagrees with Richard Mourdock's comments, and they do not reflect his views."