It is irrational to believe that a human being should not have full rights to life (please don't add all the rights of a grown person because I know that is not true for under age kids).
"As I said, Jewish law didn’t think life began in terms of full vesting or rights until birth. That’s not an irrational position."
As I stated before, this is not in the Bible.
Like I said, many longstanding traditions disagree with you on this. We might disagree with them, but that doesn’t mean they didn’t arrive to a rational conclusion on the matter.
Science has disproved these traditions.
As for the retired, There are "rational" people that state that even they are not fully human and should be euthanized.
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.