The rise of extremism is a global problem. I would agree that there is a radical left that is very vocal and influences policy (big problem here in Australia), By the same token the radical right is every bit as vocal and influences policy.
If the majority of a population become extremists, I would argue that is still the case. You’re from South Africa originally? I’m from Zimbabwe and I think it’s fair to say that the mainstream white culture was extremely racist, by world standards. That didn’t make it any less of an extreme view. Similarly examples from Afghanistan, Saudi Arabia etc.
We could argue over who is to blame and which side is simply reacting to the excesses of the other. Here in Aus it is clear that currently the extreme left is driving a backlash from neo nazi extremists.