I'm not saying I think the random jerk on Twitter is a Russian troll. Though random jerks on Twitter don't hesitate to label me as one. The reason I put "troll" in quotes is because in this sense it is a generic term for these professional spreaders of disinformation. They may be very pleasant, they may act like jerks, doesn't matter.
I'm not going to get into how I think they operate, but clearly they seem to be getting the results they want as they continue to spend their limited resources funding it.