This will be short and probably won't get a lot of attention. I've stated it in a comment, but I'm hoping a diary might get more eyes and start a meme.
I've heard that, at the two BLM protests at Bernie's events, some Bernie supporters have boo'd at the protestors. My simple suggestion is this: drown out the boos with a "Black Lives Matter" chant. This shows the protestors, the greater BLM movement, and the country at large that we support them. It is uniting rather than dividing. If the protestors feel that they are being heard and supported, they may be less likely to protest in the future and could de-escalate a confrontation instead of escalate it.
Chants need to be followed up with action. I have no doubt Bernie will back up his words with actions. Let's find a way we can reverse the division, instead of arguing with each other. Let's find ways to unite. I welcome additional ideas in the comments section.