“...occasionally suggesting protestors be subjected to violent retaliation, is influential on his supporters...”
It is not Trump’s supporters causing the trouble. It is Trump’s supporters who are being violently set upon during the rallies.
I've watched the video. I'm not buying that. Even if the protestors were violent, Trump supporters at that ralley wildly outnumber them and could easily restrain them until security could arrive. Trump offered no instructions to that effect. Instead, he said fight back, directly. Thus, he owns the consequences.