I'm interested in what attempts to cause social change actually "work."
A theory that activism never works seems no more consistent with the evidence than a theory that activism without elite support is the primary cause of social change.
On the specific example we're discussing, the evidence seems to be that the NAACP was activist, not a "ruling institution" from its founding (1909) until some point in the post-WWII period. Yet the NAACP created conditions that led to enormous social change.