That actually could be a good way to moderate political threads by requiring an even higher standard of conduct. So you must not merely be civil, but actively apply Rapoport's Rules.
I can imagine pushback along the lines of enforcing speech rules, which I'm somewhat sympathetic to. That said, I think keeping them in mind is worth it.
That's why I suggest this higher standard for only political threads. It's a lot better than banning them entirely.