In the case of Non-Sequitur, a person I and many others have had numerous dealings with, the description ‘troll’ is accurate. It results from experience.
I have many civil discussions with others on Free Republic. Only two or three are truly ‘trolls’ and I generally never talk to those. A couple more are just disagreable, nasty sorts I avoid.
All I’ve seen from Non-Sequitur is tough and logically sound (I presume his handle is meant ironically) argumentation.