We’re setting up expectations ahead of the problem. We’ve asked people to post political discussions in a particular (out of the way) location so that people who wish to opt-out can do so. I don’t think this is something we can automate into behaving, so we monitor them closely. We also have ground rules for discussions (respect, no -isms, etc).
FOr American political debates, I’ve set up monitored threads ahead of time so that people have an expectation that there is a specific thread to post such discussion in. We have a general election thread, and spin out other conversations as needed.
Nextdoor’s problem is that its community moderator tools are GARBAGE. There aren’t really moderators, in the sense we have them. I’m a community lead myself, and have no power at all. I can “vote” with the other community leads, but there’s no mechanism for actually doing anything other than reporting to the PTBs and hoping they take action (which they never do.) They don’t empower locals to take the reins. They let us kinda have some influence, but it’s not vetted, and it’s literally the first person to create the neighborhood, rather than some kind of application process that would involve training or vetting. For example, one situation we had involved the public display of the picture of a minor and shaming his parents online (he had the audacity to ride down a driveway, the horror) and the other leads voted to take no action. So the post remained up. Leads are NOT moderators.
In my community, we take a proactive approach. We know that politics are going to come up, so when they do, we keep a close eye on it and take action when needed. People who can’t play nice get the silences as needed, and we make it clear what’s going to happen, publicly. Thus far, we haven’t had much problem, but I expect we’ll be using slow posting soon.