It's probably an unsolvable paradox...

I think this blends two different issues together. I think most any point can be made in either a civil manner or in a rude manner. I may disagree with someone, but I will listen to him with respect if he or she is respectful to me in presentation. On the other hand, if a person feels the need to beat me about the head with their words, I may feel inspired to respond in kind, or, more likely, walk away and ignore them. And, most importantly, if I was the one providing the speaking platform at no charge and at expense to myself, I might very well tell that person to go spew elsewhere.

In short, I think the objectional parts of a political discussion are (usually) about the format, not about the content.

Jack