Branding any movement using exclusionary language is a strategic misstep, even if the exclusionary principle does hold validity. Effective activism necessarily entails not just galvanizing your own demographic, but in being able to successfully galvanize others in your interest and to build relationships that help you move your demographic forward. That said, the name Black Lives Matter has not been a total failure - at the very least it has given the black demographic a name to get behind.

Grabbing attention at public events I would argue is not a mistake. How they have gone about doing it, however, has been more detrimental than not most of the time I think. While they have kept their name in the press and popular attention, they have also created associations with their name which are not favorable to many people (however valid those associations may be).

Regarding their slogan (I assume you mean "Hand up, don't shoot!" and/or the various iterations?), most marching chants are fairly mindless. Slogans are very basic reductions of philosophy that are meant to be catchy more than they are substantive. To that end, I think they have been successful; they've created chants/slogans that have been popular enough to be used across the country which makes the movement seem more cohesive.

I do not think that one must be a black church leader to be honored, respected, and heeded (although that has tended to be the case in civil rights history), and it seems redundantly self-evident to state that an organizer is a community leader. I think the more important take away is that established members of community who think things through and are more intelligent about strategy and outreach are the more successful. I think religious leaders are adept at that because leading congregations fosters a transferable set of skills.

We agree, though, that running about yelling is ultimately unproductive (if not outright damaging); the Occupy movement did the same thing... and look how much change they created.

But the GoP won't listen. If they protested at those rallies, they would receive nothing but negative backlash because those people wouldn't listen in the first place. By protesting at Sanders' rally, they got him to listen and put out a statement. They got the Left-Wing establishment to listen, because the Left-Wing in this country is more likely to be open to their message. What you are suggesting simply would not work and would be a waste of their time and effort.

I think they need to go after Ted Cruz and not Tom. :P