The connotative aspect of any given word is the imaginative associated meaning of the given word. It can have numerous interpretations or meanings, aside from the given word.
Out of the four given words in the question, the word "demonstration" is the only word which seems to have a positive connotation to it. The other words such as "riot, disturbance, unlawful gathering" all suggests a violent or negative form of expression. At the same time, even though demonstration may also be used to signify a negative event, it can also be used in the positive sense.
