Honestly, I think that if your objective is to have a community based on a particular belief, you cannot have honest discussions, as you already know what you would like to talk about and it seems like you are not ready to challenge your ideas.
Let's take a look at one example from your post
Well, what about those who defend baby murder? I know lefties genuinely believe it isn't, but I do
I'm assuming you are referring to abortion rights. That is a hard take to take as a universal truth, there are many many countries where that is a guaranteed right, and you are not even considering discussing your belief. How would a honest discussion be held about this topic if you are already calling baby murderers your contestants?
Props to you for wanting to be a better moderator, but a discussion topic requires the other part to be able to freely express their opinions even if you don't like them. That would happen in a discussion community called "politics" or "United States politics", but if your community is called "conservatives", every discussion will be in the form of "conservatives are correct, leftists are murderers and terrorists" (and vice versa in a community called "leftists", what I'm talking about is not limited to conservatives) and as you notice, this polarity and fanatism attracts the worst of both parts, ready to fight and be toxic.