I think that it can be vigorously, but with respect for the other person...throwing ‘dirt’ is not my idea of respect!

I'll have a discussion but not an argument.
I try to go by this, sometimes I lose it and that's on me. I think I'm getting a little better at controlling it, I hope anyway

So long as your opinion does mean the destruction or dehumanization of other human beings rights, it's fine with me.

I think it depends on perspective..
I have got into arguements with people who it seemed like they were attacking (either me , or a gender or a group) .. looking back, i think they actually believed whole heartedly that what they were spouting was just an "opinion " even though not once , on anything they said was phrased as an opinion.

Big thing, as you mentioned.. be polite about .
If they can't (or i can't).. then i am tempted to just block or ignore that person.. especially if it looks like no common middle ground is possible.

Ideally i think you're right. In reality it depends on the person(s) you are speaking to IMHO.