It's going to be a long, scary summer. Any police or other personnel who don't have to be at the conventions would have to be insane to be there. And any police who have to be there have more legal protection if they don't respond than if they do?
That can't be right. It makes NO SENSE.
They have no duty to act, so the reason for inaction is completely irrelevant.
There might be political ramifications, the policeman might get fired, but he isn't liable in court, for damages.