Consider the contrast between these comments and the abortion debate in the US. I think the essence of the latter is a disagreement about the absolute and relative moral statuses of and rights due to fully grown humans and potential people. I expect it would continue to exist even if everyone agreed on the pertinent biological and medical facts of the matter.

I doubt that this is a descriptively accurate characterization of the debate. I'm guessing a majority of the most committed pro-life activists aren't motivated by a concern for potential people; they actually believe a foetus is a person, not just potentially a person. A number of Christian denominations preach that ensoulment occurs at conception, and that personhood (in the moral sense) is associated with ensoulment. If everyone agreed on the pertinent biological facts -- one of which is that there is no such thing as a soul -- this justification would no longer work.