Colin,
It took a while, but I eventually developed an immunity to political argument threads or other non-political threads that get derailed into political arguments. When that happens I just move along to another thread, because there are always plenty of other active topics. Hopefully you'll get to that point, too, because it really does make this place a lot more enjoyable.
As for the members who always seem to be the ones who either start the pointless bickering, or take the tiniest hint of a possibility of a political jab as an invitation to start the bickering and never let go, that's what the "ignore" function is for, and it works very well. POOF! That person is gone. I don't use that function much, but I can tell you there is at least one person whose existence I don't miss one bit, and I am absolutely no worse off for never reading another word they type on this forum.
As for having a dedicated thread/sub-forum for political and religious bickering, unfortunately I don't think it would work. The ones who derail the threads like that get pleasure from doing so, so it wouldn't be any fun for them to have to go to a specific thread to do it.