I don't think writing about abortion will automatically be downvoted, but a lot of things people want to say about abortion aren't a good fit for LessWrong. In particular, most abortion articles on the internet are about how the outgroup are obviously-wrong monsters and/or idiots. I have a vague worry that it would be hard to write something interesting about abortion given that people mostly agree on the facts (how fetal development works) and disagree about moral intuitions, but maybe you do have something interesting to add?
I wouldn't worry too much about people in the comments making a good post bad. If you're worried about it, you could just remove any off-topic comments (I think LessWrong gives post writers some moderation powers).
Eliezer gave several tests there to be applied when one considers posting on a politically contentious subject. The particular subject you mentioned is the most politically contentious of all, at least in the USA where most LessWrong readers and writers are. [ETA: It's clear from your reply to korin43 that this is indeed the specific subject on your mind.]
Discussion of such subjects observably tends to lead away from rationality. (Evidence: the Internet.) Can you hold your own writing to the required standard, and also justly weed the comments that do not meet it, showing no favour to any conclusion and judging only by the standards of rationality? You are the only one who can answer this question. [ETA: The straw man you imagined in your reply to korin43 is not a hopeful sign.]
"Social norms" are cached thoughts, simplified, memorised answers to the question of what is appropriate to post. Do not enquire of the cache, but flush it and recompute the answers yourself.
Earlier this year, the LW team added the ability to hide posts from logged out users, and to prevent newly created accounts from commenting. I think I feel better about abortion discussion if we applied those filters.
I think abortion debates are quite likely to attract the wrong sort of people, and I agree with other commenters that it'd really need to be an actively good article with a novel take in order to be worthwhile. I also think now is a particularly bad time to do it – I think there is some interesting philosophical stuff to examine about abortion through a lessWrong lens, but bringing it up right now is most likely to be swept up in a tribal conflict that is neither "effective altruism" (due to overcrowdedness) as well as not really focusing on the aspects I think LW could do a good job with,
But that all said, you're welcome to make the post. Mods might do something to limit it's visibility.
If a post had a strong opening, where it was clearly insightful on the topic and something you're not going to find elsewhere, I expect it would do well.
On the other hand, that's a high bar!
It's still a norm, but at least for me, I won't downvote if I think the post was high quality. For example, I strong upvote all of Zvi's Covid posts. On the other hand, I strong downvoted the Heard/Depp post from the the other week because I found it shallow and toxic.
I would strongly advise against posting on such topics until you've been around longer and written more on less charged subjects. You will almost certainly mess up if you try to do it right out of the gate, and nobody will give you the benefit of the doubt since you won't have a reputation to protect you.
Even if someone like myself posts about it in a way that doesn't suck, is the concern still that others will lower the quality of discourse with their comments, and downvote anyway?
When writing about heavily political topics, the bar isn't to write a post that doesn't suck. It's to write a post that's actually good. If you write a post that's at the quality level of the average newspaper article there are good reasons to vote that down.
To refer to another sequence post policy debates should not appear one sided.
When discussing a topic with potential reputational harm like the abortion debate, I think there's another impetus to make your arguments ideally in ways that use language that's intellectual enough that it's not easily quoted out of context.
Writing about politics isn't discouraged because of sensitivity, but because political positions tend to be adopted for bad epistemological reasons, have poor predictive power and little to do with rationality. Correspondingly, framing a topic politically is a good indicator that the author has resorted to poor argumentation and is very unlikely to update their views based on superior argument or evidence, which is a little annoying and not less wrong. These are general problems not limited to discussing politics but for politics it's especially bad.
The problem with political discussions is they:
a. Have almost no information in them. Often there are far more than 2 valid policies that could be considered for a situation, but the nature of USA politics mean at most 2 have any chance of being enacted. So it's literally an argument over 1 bit.
b. Most participants, even here on lesswrong, have been indoctrinated and totally convinced of 1-2 kneejerk slogans and have done no independent thought on it. For example of this I keep seeing coming up even though it's not a R/D issue: bring up nuclear energy around techies. You will instantly see a bunch of factually inaccurate propaganda they spout. Either it will be exaggerating the risks of radiation releases or a number of false claims about the benefits of nuclear power. (I bring this up because what is interesting is that both sides that typical reasonably educated people will take on this issue are false and essentially useless opinions)
c. All sides of the argument enter the argument with a deep set belief that will not be changed, and they leave with the same belief. So there was no reason to have the discussion to begin with.
I'm aware there are some sensitive subjects that have been debated to death among rationalists, if not on LessWrong, than elsewhere online, such that it would in general be fruitless to start the conversation over instead of following what has been debated thus far. I'm curious if this is considered to apply to potentially literally any single socially, culturally or politically sensitive subject. It has been several years since I've checked but my impression from before is that the prevailing norm on LessWrong was based on a particular interpretation of "Politics is the Mind-Killer" that amounts to "politics=anti-rational=downvote on site." This seems contradicted by the original post:
It seems like the alternative interpretation, though, was adopted because nobody stuck to that and so it was more convenient for reinforcing norms of civility in discourse to go with the "politics=anti-rational=downvote" interpretation.
Is that still a norm? Even if someone like myself posts about it in a way that doesn't suck, is the concern still that others will lower the quality of discourse with their comments, and downvote anyway? (I'm aware there are not formal rules but I'm in essence asking if according to social norms what categories of topics are considered forbidden by default.)