Heres my $.02 I lurk these forums quite a bit. Although I have piped into a religious or political debate once or twice, I usually roll my eyes when I see one, read 1 or 2 posts, and then go on. What angers me is when non political threads are hijacked, and turned into debates. I will also agree, every political thread is like a rerun of the previous one, just with different insults and name calling.
My suggestion? Another forum I visit once and awhile (Rage3d) had once totally banned political and religious posting. Now, they have opened up a seperate "forum" if you will. You agree by signing up for this forum that you will act mature and respectful. If not, you are banned from the politics and religion forum, but not from the rest of the topics. That way, us not as political people can enjoy the CI forum ,and not have to worry about every thread being turned into left vs right.
FAQ for P&R forum Although I enjoy politics, and even lean towards one side more than the other, I stay clear of these conversations, as I would probably get so upset that I would end up bickering back and forth as well. Anyways, sorry for the long novel, I just really think this might work out well here.