Why isn't the extreme left a reaction to the extreme right? If the statistics demonstrate that RW ideology fuels 74% of terrorist activity and LW ideolgy fuels 2%, then who is reacting to whom? When did the antifa grow enough to make the media? It was when the alt-right decided Trump was their man (whether he is or not) and began promoting their racist agenda. That, to me, looks like an extremist left wing respinse to an extremist right wing activity, not the other way around.
I think they're reactions to each other. But I believe the phenomena has gone like this: changes in demographics are fueling the rise in identity politics in the West. There's also a clash of cultures from immigrants vs the status quo (mainly caucasians). The status quo is being challenged by minorities, who believe the status quo is unequal/unfair to them, & they're also reacting to anti-immigrant & racist sentiment from the right. The right is being reactionary to these demographic changes with suspicion, nationalism, & sometimes racism as they see the changes as a threat to their culture/way of life. It's a power struggle.
This cultural demographic shift...I don't think we've seen such social changes in the West since the industrial revolution, which led to a deep polarization of politics as people tried to deal with the social changes and dueling ideologies of communism vs fascism & everything in-between. The thing with far-left vs far-right economics is that you can usually compromise & reach a middle-ground on policy, unlike identity issues, as explained well by Fareed Zakaria:
The dangerous aspect of this new form of politics is that identity does not lend itself easily to compromise. When the core divide was economic, you could split the difference. If one side wanted to spend $100 billion and the other wanted to spend zero, there was a number in between. The same is true with tax cuts and welfare policy. But if the core issues are about identity, culture and religion (think of abortion, gay rights, Confederate monuments, immigration, official languages), then compromise seems immoral. American politics is becoming more like Middle Eastern politics, where there is no middle ground between being Sunni or Shiite.
https://www.washingtonpost.com/opinions/we-dont-just-think-the-other-side-is-wrong-anymore--we-think-theyre-immoral/2017/06/15/f218c3e4-5207-11e7-be25-3a519335381c_story.html?utm_term=.61a54742cee7Canada has seen what happens when cultures clash via identity politics, with Anglo Canada vs Quebec/francophones, as well as indigineous vs the rest of Canada. In terms of Quebec, they have political power (natives have had much less power politically), & look at the problems the Quebec/french issue has led to throughout our history. The current identity divide is only going to get worse over the decades as demographics continue to drastically shift, so I'm very worried about where it will lead.