If it has been made clear that there are members who feel uncomfortable about this (Like if they state that in a message or report or whatever) then I would kindly ask the member to stop saying things which make members uncomfortable. Nobody should be in that position, whether or not it's a rule (Although I think it should be). If this discussion continues to happen (The religion and politics one) then like with the other scenario I would ask them to take it to a PM where there aren't any people who feel uncormfortable.A member of the forum is focused on politics, religion, ect... but it is their own opinion... however their posts have people mixed with their own beliefs and has been upsetting a few of the other members for making the forum awkward. How would you handle this situation even though they aren't technically breaking any rules?
However since this isn't an official rule I wouldn't take warn action unless a higher up says so. (Like an Admin).