Fundamental problem
Twitter has problem with its basic design. It tends to be oriented towards loud-mouthed, vain, narcissists who by definition at best only obnoxious. The more obnoxious the more trollish the behavior. It is not a platform designed for something resembling a coherent post, 140 characters pretty much limit one to snark. A longer post allows one to express more subtlety, facts, and, hopefully, logic about a topic.
The problem with trying containing trolls is very basic. What is a troll? Outside of some very loutish people it is often in the eyes of the reader; particularly if the topic is controversial such as the recent US election. Too many define a troll as someone who disagrees with them or expresses an observation which may very accurate they wish to ignore.