I believe that certain cases of assault should be weighed with respect to the fact that the person who threw the punch (or kick or headbutt or elbow or whatever) may have been enraged through deliberate verbal taunts, however I believe that such a justificaion typically should only apply when such 'fighting words' are directed specifically toward the assailant beforehand rather than a general proclamation to all who might be within hearing range. A person holding up a sign that says "THE USA SUCKS", but doing no more than that, is not instigating a fight. So long as they do not directly taunt any individuals nor violate any laws, they should be allowed to continue standing there for as long as they want so that all may see what an idiot they are.
"I believe that certain cases of assault should be weighed with respect to the fact that the person who threw the punch (or kick or headbutt or elbow or whatever) may have been enraged through deliberate verbal taunts, however I believe that such a justificaion typically should only apply when such 'fighting words' are directed specifically toward the assailant beforehand rather than a general proclamation to all who might be within hearing range." 99 times out of a hundred, I would agree with you. However, some of the signs the protesters have been waving are downright enraging. I saw one (on the news) that said, "We support the troops when they shoot their officers." If I had seen that for real, there would be a chance I would have been set off, and I'm not one who is ordinarily prone to violence.
I don't think assault on protestors is right. But considering the mitigating cirucmstances, if I were a judge, I would say disorderly conduct, suspended sentence, and if you stay out of trouble for 90 days your conviction gets expunged.
OTOH, it seems like the protestor may have struck first. Dunno on that one.