I am not entirely sure - do you have any suggestions?
Possible Hypothesis: Assess how the Black Panther Movement had a definite style and significant support yet achieved only a small measure of success in the struggle for Black Civil Rights
Your, hypothesis sounds really interesting. With it though, you might have to be careful (or alternatively include it) the 'definite style' you will have to examine, as they were portrayed quite critically in the media, and you may need to look into this, to make sure you are getting their 'movement style' and not the exaggerated one by the media, or examine if this one was in fact the correct one (this was actually my topic, so If you need help, just PM me!). The second part of your thesis is good, however you might come across academics/historians who beleive differently, and this is good! A historical debate within your essay is what you want, so differing points is what you want, just make sure you make
your point clear.