Many people have a rule about not discussing politics or religion. There's actually a very good reason for that: most of us use politics and religion, not as a philosophy or theology, but as a means of defining ourselves and placing ourselves within our vision of the social spectrum.
Most people don't mind if you challenge a philosophy they espouse, but if you challenge their politics and they use their political affiliations as a means to define themselves, then you're posing not an intellectual argument, but a threat to their very sense of being.
Humans are social creatures, but we're not communal (like ants or bees) so we constantly seek ways to position ourselves within our affiliated cultures and sub cultures. Because we can't actually surrender our individuality to the group, political and religious affiliations and behaviors become a prime method of expressing our desired social position. It becomes a matter of security and has a strong impact on our sense of well-being.
I actually love discussing, even arguing, politics and religion and philosophy. I find it very stimulating, but I've learned through the years that many times I should avoid it because the people I'm arguing with don't see it as an intellectual exercise, they see it as a challenge to their espoused sense of self, and honestly, I don't have a right to do that just because I enjoy discourse.
It's hard though, because the more a person uses these things to define themselves, the more illogical their arguments become and it's really, deeply difficult for me to leave an illogical argument laying on the table.
I am a gentleman though, (or at least I try to be a gentle person) and although I still slip up a lot, and it's not up to me to correct anyone on how they should define themselves, so I do try and bite my tongue quite a bit.
I do fell sorry for them though. This business of trying to define ourselves (socially in particular) is a fruitless effort. We are, by nature, utterly individual and undefinable. This concept of society and culture is really just an illusion we came up with to try and cover how very individual and alone we all are. Often I get the sense that the people who try the hardest to define themselves socially are actually the most lonely and the most insecure.
I get this outlook from my grandfather. Although my grandmother never agreed, my grandfather thought the people who ran around town joining every club and going to every party were fairly silly. As a result, he formed his own club with the express purpose of not trying to establish yourself socially, but to be silly and laugh at being silly and to use social situations, not as a means of positioning yourself, but as a time to enjoy friendships.
It was something of a horror for him when the second generation members in his club began to turn it into the very thing he and his generation formed the club to be against. Since there were already several clubs dedicated to men trying to position themselves socially, my Grandfather's club was no longer unique and since it lost its purpose, it eventually folded from lack of use.
If you know me, then I probably have argued politics or religion with you at one time or another. Please understand, for me, these things are pretty impersonal and external. Intellectually I know this isn't the case for most people, but like everyone else, I'm pretty much locked into my own point of view on the universe and it's often difficult to remember the way I see things aint necessarily so for anyone else.