Careful using terms like "always," as stereotyping/sweeping generalizations are rarely factually correct; however, if your point is that Republicans/conservatives do not riot or protest or clash with police, I can agree.  What would conservatives be "losing" that would cause them to riot?  

A more obvious point that could be easily made here is that protestors are rallying against one particular conservative candidate.  (Do we see these incidents at a Cruz rally, for instance?)  Furthermore, it may not be just the "left" that is protesting.  (Does anyone interview the protesters to see if they have any ideological/political affiliations at all?)  More likely they are younger (drawn to protest like moths to a flame) non-voters who are, nevertheless, against the inflammatory rhetoric that this particular candidate is known for.  

RE: your use of the term "left" -- I would suggest that the majority of Americans are "left of Trump," not only the FAR left which is what I think you meant.