Well, I wouldn’t be at a Bernie Sanders event for any reason so I wouldn’t very well be able to sit there and shrug or do anything else. Some things are worth fighting for. Putting your body on the line to help a college girl troll some dumb Bernie-bots isn’t one of them. By wise council shall you evaluate conflict, not by charging into any and every situation head first.
You can react how you want, the sequence of events I outlined are not an opinion, it’s simply what would occur if someone were to react physically to the situation. If those consequences are acceptable to a given person, and they decide to cause a scene, so be it.