The violence at trump rallys is instigated by the unwelcome protesters in the venue. The right to assemble is not the right to violently disrupt. When protesters instigate i.e.: scream nazi, burn flags, throw eggs, refuse to follow direction of the police, secret service, and security personnel. Fights break out. Remove the instigators and there would be a peaceful rally for people to make fun of and disagree with. Now all you get is more anger, more hate, and you grow Trump's base of support exponentially.