I think that while its certainly ignorance. it's more about complexity (which ignorance thrives in), wherever complexity lies, divisions do as well. ignorance itself does not necessarily have to be wilful. I suppose I'll say, this is not a counterargument, I somewhat see your point and wanted to expand on it.
That's a good point. It's also often the case that the differences aren't as big as they seem to outsiders. One of the benefits of going abroad for a while is to be able to see your own country's politics from a distance, and the one your in's closer. It's easy to see that the Overton window is often quite narrow.
However, I don't know many places where mainstream politics would accept political violence as anything but extreme in almost every case. I'm not sure the fringe is growing, but to come round to my initial point, I'm worried that it will after the last WWII generation dies out.
