I often see "extreme" used to describe merely moderate right-wing or conservative positions in Europe. I don't see "extreme" used to describe hardcore communist, socialist or "progressive" politicians, leaders or supporters. I believe it's a label often used by the left there to malign opponents and silence debate, like "racist", rather than open and maintain a dialogue.

Still, it could very well be an overreaction on my part.

However, it must be asked, what is it about French or European society today that creates this 15-20% support for these "extremists" in the first place? The right-wing seems to be very reactionary in Europe, so what current form of at least perceived extremism is already prevalent in French/European politics and society to give form to this backlash?