The point is that the people who come to conclusions different than you came to are not, by definition, irrational, nor are their conclusions irrational.
I think a person can look at the facts and decide that a fetus 6 weeks along isn’t the same as a fully formed born infant, nor the same as a young child, nor an adult.
I disagree with their policy choices, but that doesn’t mean their conclusion on this matter is patently wrong. Different people can look at the same facts and come to different conclusions.
Great, as soon as "rational" people decide, on the same "rational" basis as the "rational" choice to kill a baby in the womb, to eunthanize retired people (like they "rationalized" in Denmark) because they do not contribute anymore I will disagree rationally.