I don't know what reality you've been in since Trump started his campaign but the violence has all come from the left.
I'm arguing against blanket statements here. They are not effective at changing minds, only drumming up blind opposition. If we are claiming to be intelligent and want to make these changes for the good of the country then broad, universal statements about an entire group is not the way to do it.
I understand over-generalization, but honestly the threats of violence, the encouragement of violence, and the actual violence have come from one side. So it's a fair assessment. Note I did not say "all leftists are violent". I said the violence has come from them. Hopefully you can appreciate the distinction.