Yes, it is possible for LW community members to have productive discussions about politics. But not online, only in person (or maybe in small-group video chats). In person, it is possible to defend the quality of discussion by modelling the other participants to find common ground, and by excluding anyone who's particularly disruptive. Once an in-person discussion has formed, no one can dominate it just by spending more of their free time. On the internet, many topics will summon angry outsiders through Google Alerts; people with empty lives dominate because they have more time to spend; and and the participants are too many and too invisible to model.