I listened to the video from the other thread on this. While I am grateful that nutcases were ejected, after listening to the video, I can't understand why anybody would waste their time arguing with these nuts. JUST ignore them and enjoy your meal, you have absolutely no chance of them understanding logic.
If it had happened to me, I would have went to management and told them they were disturbing my meal. I would not have made even one attempt to communicate with them.
Firstly, there's a video? I haven't found it. Found a thread in the Oklahoma forum but didn't see a video link in it.
Secondly, as to your second paragraph, I agree wholeheartedly. Engaging them even in an attempt to have a rational discussion is not something I'd do. For the most part I think I would apply the same policy to "them" as I do the police. Sort of a, thanks but no thanks, I'd rather not talk to you sort of approach.
Edit: To clarify, I don't mind talking to the police, as long as it's outside the context of a stop or investigation. Of course, "anti" people can't detain me, but I'd consider a "confrontation" generally along the same lines.