Trump and the others: what´s happening?

The challenge I have been confronted with today is very clear: how can we explain the wave of popularity on which Donald Trump, Bernie Sanders, and Jeremy Corbyn are riding?

Not long ago, people like them and others similar would be looked at as oddities at the margins of the political spectrum. Their support would have been peanuts. Now, they are mainstream leaders and, at least in the case of Trump, not too far from getting to a position of real power. And they have caught us by surprise. 

What does it say of the social environment in our Western societies?

This is a critical question. It calls for a very serious debate. It´s not enough to say they are mere populists. That is a very incomplete explanation.