1. Sexual intercourse may lead to pregnancy. (ie accepted risk / implied consent / informed consent) 2. A fetus can feel pain 3. A fetus is a human being/person 4. Morality There are others but these will do for a start, anyone care to debate why they are red herrings?
Well, they're essentially distractors. I'd say all (but the first) are subjective, and leading the debate toward a false conclusion is textbook red herring material.
I'd add that they dishonestly try to conflate "human life" with "human being" and vice-versa, to give the impression that one second after fertilization of an egg, it becomes a "person".
I happen to agree with your premise, but I have to say that the way you have framed this debate somewhat precludes real discussion. It assumes agreement, reducing the conversation, let's tell each other what we all agree on, with slight variations. But here is what I will attempt to contribute: 1. Sexual activity as a red herring: For one thing, this makes several assumptions which are not definite and these are 1) that the sex was consensual in the first place and 2) the woman is sufficiently educated to make an informed decision and 3) the woman had unprotected sex. There is no contract to sexual activity. No legal or binding contract of any kind. 2. A fetus can feel pain. This is irrelevant, as a number of creatures can feel pain. 3. This is a philosophical distinction 4. Morality is much too subjective, and too easily tied with religious doctrine to form a basis for secular law.
I am more than happy for anyone to disagree and enter into a debate as to why they disagree and why I disagree with them. 1a. That sex was consensual in the first place - doesn't matter, consent to sex is not consent to pregnancy. 1b. the woman is sufficiently educated to make an informed decision - doesn't matter, informed consent is not binding it only applies until the person, by word or action, explicitly says "no" 1c. the woman had unprotected sex - Doesn't matter, see reply to 1a.