It is a legitimate criticism.
Trump says demonstrators should be roughed up. That he wants to punch them.
Trump supporters do not go to a Trump rally to punch another Trump supporter, nor would any republican go to a republican rally expecting to be stand along side a Bernie Sanders supporter.
Can you show me some video of the protestors being violent? Not being smart assed I really want to see where there was unprovoked violence by a protestor at the rally.