Canada

The polarization is a product, a symptom, not a cause. Look at the economic processes affecting everyone. They drive the political processes, part of which is polarization. Simple example - if I can't find a job as a young guy, see no feasible way to move out of my parents' basement, therefore have little chance to court a girl and have a family of my own, I'd be pretty angry and looking for the cause of my misery. Seeing all these new people on the street that weren't here a few years ago would be an obvious candidate. The axes on which polarizarion occurs aren't new and unnatural, and people have found the same explanations for their misery in the past, way in the past. Not all of those explanations are valid of course, but the economic misery driving to them is real and the march towards polarization won't stop until the misery recedes.