What this means is that the successful advocate exists in a peculiar state of functional delusion and cold calculation. It means having a pair of rose colored glasses but keeping them perched on your forehead, lest they obscure too much. It means spending oneself recklessly and, of necessity, repeatedly losing heartbreaking battles because failure is always, ALWAYS, an option. And despite utter, soul-crushing disappointment, getting back up and going for another round.
But even if one achieves this perverse state of functional madness, the successful advocate faces one last trap -- the seductiveness of martyrdom. By this I do not mean true martyrdom of dying for one's beliefs, or even genuine figurative martyrdom of those willing to endure in the face oppression so as to create an example of resistance or to shame others into action. By martyrdom, I mean struggle with no hope of victory and no goal in defeat.
Martyrdom allows you to define failure as success. Martyrdom converts bone crushing defeat into a sort of sick pleasure, and therefore defeat becomes a self-fulfilling prophecy. Martyrdom is its own reward, and its own prison. After a time, the failure becomes necessary, confirmatory that previous failures were not your fault but the inevitable way of the world.
Those looking for world-changing advocacy should therefore embrace madmen but shun martyrs. The unfortunate history of social movements is that they tend to get this backward.