Most people undoubtedly understand quite well that medical research is vital and that people have a right to abortion and a right to donate the fetal tissue from their own body to that cause. They appreciate that horrifying diseases like polio were eradicated via this process and want to see actual living, sentient humans saved in the future from dreaded diseases like ALS and Parkinsons.
It seems completely absurd to a thinking person that anyone would think it's more important to keep a dead fetus intact than to allow it to help save living people who are suffering. It's really not a controversial concept.