One of the most tragic examples of this failure was the Spanish Civil War. Of course, history doesn't repeat itself exactly. And the internet really does fundamentally change the dynamics of human movements. But yeah... a refusal, on the left, to be led, to coalesce, played a big part.
Now, it may be a failure of imagination on my part to see how an effective resistance is possible without concrete leadership. I hope so. Because our appetite for rejecting the imperfect seems limitless to me 7/