"Bad Actor." You know, not a clueless thespian, but an actual "unruly, turbulent, contentious individual."
A shit-stirrer. Sometimes you want to stir the shit, or maybe sometimes it's good for the shit to be stirred. But sometimes not.
Just like anything, it all depends on the time, the place, the circumstances. A bad actor can be a useful, necessary phenomenon, or a very negative, corrosive entity.
Right now we are being inundated with the thoughts and actions of a very, very bad actor. It's a sensitive time for our Democracy. And maybe it's all a lot more fragile than we think.
How bad can things get? I suppose we will find out...