If you approach the media/political space as a control system, it is unstable -- it's oscillating.

These fringe people desperately want to be heard, as a free society we want to allow them to speak, the media needs eyeballs and these fringe elements collect eyeballs. These eyeballs are "sticky" and form clumps. As the clumps grow, the fringes are happier and the media is happier. Our almost cost free, instant communication capability adds "gain" to the system. As these growing clumps collect more and more energy with each cycle, the machine eventually breaks apart.