Polarization Pointer
I came across this tonight; it's a good partial explanation for the flaws I've found in the various movements I've been involved in (or opposed) over the years. It's part of that story where various good-intentioned people and movements end up with a cultural rot that hurts rather than helps their cause, where people judge claims not by their soundness but rather by their being on the "right" side of an issue, and how some people eventually convince themselves that "fuck you" is actually something reasonable people say in an argument.
I say it's a partial explanation because it doesn't deal with memes in discourse, and those are pretty important; movements develop little verbal tics that are easily confused with actual points, and it takes an unusually careful person to be able to notice those and challenge them in order to get discourse back into good shape.
(I've been posting here a bit less often; been more active on G+ recently, and I'm trying to save this space primarily for longer original content rather than commentary)