You see the same pattern over much of the world. In three consecutive presidential elections in the United States. In the latest polls in Britain, where the 2016 Brexit referendum was the first notable outbreak. In France's most recent national election and in Germany's. In Canada's election last month. And maybe in Poland and South Korea last weekend.
The pattern can be summarized in a simple formula. M+M versus H. Or, increasingly and to the discomfort of established politicians and press personnel, M+(1-x)M