How could Ben Carson's fetal tissue research affect his campaign?

The Republican candidate and retired neurosurgeon has defended his decision to use fetal tissue for medical research more than 20 years ago.

Weeks after decrying the use of fetal tissue for medical research, Ben Carson has admitted to using fetal tissue for his own research purposes while working as a neurosurgeon. 

Carson, like many of his fellow GOP candidates, has called for the defunding of Planned Parenthood following a series of controversial videos released by an anti-abortion group which purportedly show officials from the organization discussing illegally selling tissue from aborted fetuses to research companies. Planned Parenthood denies any wrongdoing, saying that their employees were discussing legally donated fetal tissue for medical research.

Last month, the presidential hopeful told Fox News that the benefits of fetal research have been “over-promised” and “very much under-delivered,” adding that “there’s nothing that can’t be done without fetal tissue.”

But Carson’s stance on the issue was called into question on Wednesday when obstetrician-gynecologist Jen Gunter uncovered a 1992 research paper co-authored by Carson, in which he describes using “human choroid plexus ependyma and nasal mucosa from two fetuses aborted in the ninth and 17th week of gestation.” 

“As a neurosurgeon, Dr. Ben Carson knows full well that fetal tissue is essential for medical research,” wrote Dr. Gunter in a blog post, noting “the hypocrisy of actually having done that research himself while spouting off about its supposed worthlessness.”

Carson maintained in a statement issued Thursday, however, that there is “absolutely no contradiction between the research I worked on in 1992 and my pro-life views.” 

“The issue of fetal tissue has everything to do with how the tissue is acquired. My primary responsibility in that research was operating on people to obtain diseased tissue for comparison to banked tissue samples,” he said. “Killing babies and harvesting tissue for sale is very different than taking a dead specimen and keeping a record of it, which is exactly the source of the tissue used in our research.” 

These accusations of hypocrisy have led some to question how this new information could affect Carson’s chances of earning the Republican nomination.

A recent Gallup poll showed that abortion is an increasingly important issue for voters, particularly those who identify as pro-life. Twenty-one percent of Americans surveyed said they will only vote for candidates who share their views on abortion, the highest percentage in 19 years. 

The survey also noted that the percentage of Americans who do not see abortion as a major issue – 27 percent in 2015 – has been on the decline in recent years. 

“Although abortion is a defining issue to at least one in five Americans, its influence on the 2016 election is likely to be limited as long as each party's candidates continue to espouse their respective party's abortion canon,” the survey summarized. 

A CNN/ORC poll released Wednesday showed Carson in second place behind Donald Trump with 14 percent support in Iowa.