As someone who used to support the movement, and as someone who still supports what the movement stands for, I have to say I am extremely disappointed in their actions.
I would be OK with the protest, if it lasted for a minute, but it dragged on and on and on. I would be OK if they protested someone who disagreed with them, but they drowned out Sanders who supports them on the very issues they are fighting for and in fact has outlined solutions to their issues. They showed utter disrespect for Sanders and I was astounded.
Here's the thing. The optics are embarrassing for BLM and for Sanders and for the Democratic party as a whole. Furthermore, these tactics only serves to alienate people. Frankly, they turned me off, and I'm sure I'm not the only one.
Their tactics make them appear aggressive and self-centered and rude (possibly even bullying). How would BLM leaders feel, if they are discussing the deaths of black americans , someone got up and shouted incessantly about global warming though out the entire speech? Surely, global warming is an important issue. Surely, it is an urgent issue. Surely, it affects the lives of millions of not billions. Surely, it's an issue that requires speaking truth to power. Does that make it OK to interrupt a speech by an ally on another issue, and shout all the way through the speech? I don't think so. Everyone who thinks that BLM was right to do what it did to Sanders should be OK with this scenario.
It was also confusing. Normally you protest your opponents. I actually got confused and thought that Sanders did not support the movement. I had to research his position to figure out what was going on. Such aggressive protesting of an ALLY is counter-productive, but also serves to confuse everyone who aren't so deeply involved in understanding everyone's policies.
They need to show others the same respect that they deserve. I promise you, they aren't winning any new allies. And they are likely losing old ones. I want their movement and their desired policies to do it. But this is NOT the way to go about making it happen. That's the reality.