In my experience, internet communities form around content. An analogy I like to use:
If you go to a concert, you probably come for music, not the audience. That’s what happens with online communities too. If anything, other people must be endured. Once the venue stops hosting music you care about, you’ll think nothing of doing something else with your evening. It’s all about content.
But you might notice other people who seem to have a different, or maybe deeper, draw. The couple a row or two in front of you flag down a friend finding their way to their seat. The guy behind you knows all the lyrics to every song and proves it by singing (badly) into your ear. You see tour shirts from other continents. This is the part of the community that, in a sense, transcends the content, which is the only way a community can sustain itself.
This is a perfectly workable foundation for a community. The line between open-source movements and political movements is indeed thin. One difference, however, is that a contribution to an open-source project has immediate impact. If I can fix a bug for myself, that’s satisfying. If I can fix it for every other user of the software, that’s empowering. There’s hardly anything like that in politics.
My son recently got involved in local politics. He advocated for a bus-friendly change to a busy road in our city. At the city council meeting he had 3 minutes to make his case. Other people (some for and some against) the change made their statements and the council voted for a version of the change. This is probably the best case scenario for having influence in politics and the change will take several years to be completed.That’s if all goes according to plan.
Discourse is a fine option for political discussions. A few years ago I set up a private category for a very active community that loved to talk about politics. Moving these (often contentious) topics to a private category was a key factor in the community’s renewal. Discourse’s tools for moderating allow us to keep the discussion relatively civil. Starting an online community from scratch is just a lot harder than moderating an already mature community.