A fourth secretly shot video claims to show Planned Parenthood executives negotiating the sale of fetal tissue, and conservative Republicans are calling to defund the organization.

"The concept of tax dollars being used to fund an effort that commercially sells harvested body parts is something that I would support stopping," says Rep. Lee Zeldin (R-Shirley).

Nassau Planned Parenthood CEO and president JoAnn Smith says her organization has done nothing illegal. Smith says Planned Parenthood uses most of its funds to promote sex education and contraception for its thousands of patients.

Political analyst Mike Dawidziak says the issue of fetal tissue research and abortion is quickly becoming a hot presidential campaign issue for 2016.

"Issues come and go in politics, but right now this is a real red-meat issue for the Republicans," says Dawidziak.