Nixonland points out something interesting and still relevant. Dr. Martin Luther King Jr. may be a sanitized figure in death but, as I've written about in the past, he was hardly a consensus figure in life.
The strategy of his wing of the civil rights movement was to disturb the (illusion of) peace and draw out the hatred that was really there, but lurking just beneath the surface.
The book also points out that the civil rights movement was adamant in NOT being linked to a particular political party, but rather to an agenda. When some Democrats refused to push, or even obstructed, parts of their agenda, the civil rights movement did not hesitate in encouraging people to not vote for Democrats.
They recognized that threatening to withhold their vote - and being willing to actually do it - was the only real leverage they had on legislators. They refused to reward people who crapped on them. They were about their agenda, not about a particular party.
I wonder if Occupy sympathizers will heed this lesson.