Buy a gun. 2A.
Prepare for a world in which you have to defend yourself because help is not coming and the bad actors know it.
Edit: To be clear, this isn't a good reason to go out and buy a gun. We already know that the help isn't coming, which is why the police should focus on real crimes.
I think you could argue that the cause of violence is the massive imbalance in power between the people involved. Ideally the risk of actual consequence might dissuade police from acting thoughtlessly.
Edit: specifically referring to the violence at protests, not broader violence issues. It’s worth remembering that Americans have a first amendment right to protest peacefully.
Look at what happens anywhere there is a police vacuum. Be it Somalia, Mexico, Paris Suburbs, South African townships.