People make and possess child pornography even though it's illegal, but somehow pro-choicers don't think that's a valid reason to legalize it.
I'm against making cameras and photography classes illegal to stop child pornography, just as I'm against making trained medical professionals and sex education literature illegal to stop abortion.
A world where abortion is illegal (see pre-1960s America) is also a world where it is illegal to talk about considering abortion. This means taking abortion away from doctors and educational outlets like Planned Parenthood, into the hands of profit motive black market abortionists whose motives aren't planning, but to sell as many abortions as possible and whose motives after the act aren't for scientific research but, again, to sell as much tissue as possible.
Banning abortion isn't banning abortion. It's banning medical, educational, and scientific discussion of abortion. Pro-choice is banning abortion, as in banning abortionists, and providing legal protection to the science.edu community.
If I'm a shrewd pro-abortionist businessman looking to make serious amounts of profit margin in the selling fetal tissue, the gameplan in starting a pro-abortionist movement in my favor would be:
(1) campaign to pass educational reforms to abstinence only education, to increase the amount of unwanted pregnancies out of the public school system
(2) campaign to ban late term abortions and speed up the process so uncertain prospective are pressured into making an immediate decision under less emotional circumstances
(3) campaign to reduce the number of abortion clinics in local areas to consolidate competition and strengthen bargaining power
(4) campaign to phase out federal funding to increase clinic financial stress to sell tissue
(5) campaign to expose these practices, causing there to be trust issues with unknown competition and driving up costs
The only thing that needs to stay legal is the rape/incest clause, a window allowing the possession of the tissue to exist, but by cutting federal funding and restricting everything else, it makes tissue acquisition in a black market highly profitable for the abortionist.
It wouldn't surprise me if vocal Pro-Abortionists in this thread like DC Al Fine and Jacobtm have some retirement money invested away in these kind of businesses.