Is it possible for an individual to be "pro-life" yet allow the killing of innocent unborn children in certain instances?

During the U.S. Republican presidential debate on Saturday night, three candidates called themselves "pro-life" but said they supported certain exceptions to abortion.

Moderator Mary Catherine Ham asked how Republicans would react to the observation that they are losing the youth vote on certain social issues, such as gay rights, while also noting that "young voters have not moved to the left on abortion."

Florida Senator Marco Rubio replied by describing abortion as a "human rights issue" and "not a political issue."

"It's a difficult issue because it puts in conflict two competing rights. On the one hand is the right of a woman to choose what to do with her body, which is a real right. And on the other hand, is the right of a unborn human child to live. And they're in conflict," Rubio explained, as quoted by Christian News.

"As a policy maker, I must choose which one of these sides takes precedence. And I choose to err on the side of life," Rubio said," he added.

Later on during the debate, however, Rubio said that he supports certain allowable circumstances for abortion.

"I do support the exception of the life of the mother because I'm pro-life," he said. "I just believe deeply that all human life is worthy of the protection of our laws."

Former Florida Gov. Jeb Bush, for his part, described himself during the debate as "the most pro-life person on stage," but also expressed support for abortion exceptions.

"I'm pro-life, but I believe there should be exceptions: rape, incest and when the life of the mother is in danger," Bush explained.

"That belief, and my consistency on this makes me, I think, poised to be in the right place of the sweet spot for the Republican nominee. ... I think that we have to be cognizant of the fact there's a lot of people that are concerned about having a pro-life position without any exceptions," he added.

New Jersey Gov. Chris Christie, for his part, also said that he believes women should be allowed to abort their unborn children in certain cases.

"I believe that if a woman has been raped, that is a birth and a pregnancy that she should be able to terminate," Christie said. "If she is the victim of incest, this is not a woman's choice. This is a woman being violated."