[CliffFletcher]

I don't think it's useful to see this only in terms of American politics in the least few years. This polarization and magnification of the voices of extremists is not confined to the U.S., and it predates Trump and Obama. You see it in the UK too, and increasingly in Canada as well. When a Liberal or Conservative politician would make a mistake or a gaffe, he'd give a half-hearted defence and then move on, and his colleagues would ignore it. Now, the opposing party is villified for even raising the issue, and the party closes ranks and defends their own to the hilt. It's us or them, black and white, attack attack attack. Moderation is seen as weakness, compromise as treason.

And it goes beyond formal politics. I was recently sanctioned on a hobby forum for taking a fairly moderate stance on an issue that some activists were up in arms about. I doubt more than a fraction of the people in this hobby care about the issue. And yet a movement is emerging that will almost certainly rip through the hobby, leaving dozens of flames wars and a divided hobby its wake. That's the power of a small and intensely motivated cohort to completely dominate discussion in today's social media environment.