Simon:
The neo-nazis / extreme right were not any threat, they were a fringe of a fringe who could barely fill a small room. You will never eradicate such groups completely but they were really nothing.
I agree! (with the fringe-bit. Not the small room-bit since I do not know).
The nut-left created themselves because they kept being given more and more power and influence. When that happens, it never gets to a point where people say "OK, thanks, we have enough now!". They want more ... and more
I 100% agree
At some point, there is a rejection of it because it all goes too far. Now, for some people, you're a nazi just for being white or a rapist just for being a man and having the audacity to exist.
I 100% agree. Those people are irrational. They are hurting the public discourse and prevents us from focusing on real issues, even issues they care about (Treatment of women in Islam).
But here is the flip-side.
The nut-left grew (as a matter of fact) in large parts by convincing its adherents that the Nazis and KKK were really not just a bunch of hillbillies in trailers in the backwater of nowhere but that "they" were actually in control... that society was systematically oppressing women, that racism is as ingrained in society as ever before and if you do not agree you are part of the problem.
That propaganda mostly consisting of real, actual grievances that were repeated again and again. And so the nut-left created an alternative reality where everyone else were not the enemy and there was a high demand for ideological purity. That is why you can de-platform a woman like Hirsi Ali: While they recognize (at some level) this is unfair to her, they do so for a higher cause (fight oppression of all women as they see it).
Causally, the Nazis, the real violence against women etc. is involved in that story, but that does not mean you can fix things by fixing the Nazis. Just like poverty and oppression is involved in many Islamic terrorists stories if you go back, that does not mean we fix the problem of Islamic terrorism by making it about poverty.
Then we get to the nut right... Yes, causally the nut-left is involved. The breitbart propaganda's solution for everything IS to point fingers to the nut-left after all and you can read the comment thread to see that the liberals have morphed into something as scary as the patriarchy for the typical breitbot.
However, the nut-right is also full of lies, exagerations, propaganda. Often homegrown, but in part also systematically spread by a hostile government... the same crazy you see on the left is at work on the right, just give it time and you are going to see the calls for ideological purity. Did you know it is widely known on the alt-right that McCain is a senile old fool? Watch the language. Notice how when someone from the GOP points out Trump lies they are "attacking" Trump. What should we do when a lapsed soul attack the dear leader?
Then there is the science-denialism... the conspiracies (voter fraud & birtherism)... the thinly veiled racism (just read the comments).. the (and this is the big one!) endless pessimism about everything. Sounds familiar?
All this has been around for decades, and is being fed into the SJW propaganda mill who lab it up and tries to paint every conservative in this mold.
It is the same type of crazy and errors that are going around. We can't say that the cause of the nut-left is the nut-right (even though they figure in their propaganda) any less than we can say the cause of the nut-right is the nut-left (even though they figure in their propaganda).
Right now I focus on the nut-right because they happen to be the ones in power.