Republican presidential candidate Ben Carson compared abortion to slavery in an interview on Sunday, insisting women who are raped or victims of incest should not be allowed to terminate their pregnancies. “Think about this,” Carson said on NBC’s Meet the Press. “During slavery—and I know that’s one of those words you’re not supposed to say but I’m saying it—during slavery, a lot of slave-owners thought they had the right to do whatever they wanted to that slave, anything that they chose. And what if the abolitionists had said, ‘I don’t believe in slavery but you guys do whatever you want’? Where would be?”

Carson, who is challenging Donald Trump for the role of frontrunner in the battle for the GOP presidential nomination, said he would “love” to see Roe v. Wade overturned. When asked whether there could be exceptions that would allow abortions to be carried out in certain circumstances, he said the issue could be discussed.

“I’m a reasonable person. And if people can come up with a reasonable explanation of why they would like to kill a baby, I’ll listen,” Carson said. But he made it clear that the only room for discussion had to do with the “extraordinarily rare situation” in which the mother’s life is at risk. “Rape or incest, I would not be for killing a baby because the baby came about in that way,” Carson added.

This is hardly the first time Carson has compared something to slavery. “Obamacare is really, I think, the worst thing that has happened in this nation since slavery,” Carson said in 2013. “And it is in a way, it is slavery in a way, because it is making all of us subservient to the government, and it was never about health care. It was about control.”