Sen. Rand Paul (R-KY) went on CNN's "Situation Room" Tuesday evening to discuss the Life at Conception Act, but he ended up surprising the political world by floating a seemingly pro-choice argument.

Insisting that "there are thousands of exceptions" to his latest proposal to extend the rights of personhood to fetuses -- a move that would make all abortion and some forms of birth control illegal -- Paul told CNN host Wolf Blitzer that "decisions made privately by families and doctors" will not be covered by his proposal.

"Just to be precise, if you believe life begins at conception, which I suspect you do you would have no exceptions for rape, incest, the life of the mother is that right?" Blitzer asked.

"I think that once again puts things in too small of a box," Paul replied. "What I would say is there are thousands of exceptions. I’m a physician and every individual case is going to be different. Everything is going to be particular to that individual case and what is going on that mother and the medical circumstances of that mother... There are a lot of decisions made privately by families and doctors that really won’t, the law won’t apply to, but I think it is important we not be flippant one way or the other and pigeon hole and say this person doesn’t believe in any sort of discussion between family and physician."

That's a sea change from Paul's prior position on abortion, as The Atlantic Wire pointed out. A Kentucky Right to Life survey in 2010 shows that Paul opposed exceptions for rape and incest, opposed hormonal birth control like "the pill," and supported a theoretical constitutional amendment banning all abortions by extending personhood to fetuses. He also told The Associated Press in 2009 that he feels opposing abortion in cases of rape, incest and when the mother's life is at stake is "an honest position."

Pressed by Blitzer on whether that means he believes in exceptions to fetal personhood protections, Paul repeated his claim that there will be "thousands" of exceptions dealt with on a case-by-case basis.

"There is going to be, like I say, thousands of extraneous situations where the life of the mother is involved, and other things that are involved, so I would say that each individual case would have to be addressed," he explained. "And even if there were eventually a change in the law -- let’s say people came more to my way of thinking -- there would still be a lot of complicated things the law may not ultimately be able to address in the early stages of pregnancy. That would have to be part of what occurs between the physician, and the woman and the family."

The National Abortion Federation estimates that 88 percent of abortions take place in the first trimester. The Supreme Court’s decision in Roe v. Wade also said late-term abortion bans could only be enacted when fetus becomes viable outside the womb, usually around 22-24 weeks into the pregnancy.

This video is from CNN, aired Tuesday, March 19, 2013.