I do want to say that it's definitely not just the electoral system. The general theory in political science suggests that it's both what we call the social cleavage—the structure of society, the issues, the ideals that are in society—as well as what we call the permissiveness of the electoral system, how tolerant it is of small parties. It is definitely a combination. On top of that, we know that severe economic downturns also enable the rise of such sentiment, so it's definitely not just the electoral system.
On September 28th, 2016. See this statement in context.