Rising political populism is an immune response to structural imbalances.

Many people think this trade war just happened out of nowhere. There's some truth to that, meaning that Trump didn't have to engage in it in the way he did. But you have to look back several steps to get a bigger picture.

The way the dollar reserve currency system is structured, the world needs an ever-growing number of dollars, and the US supplies those dollars via a permanent trade deficit. Those two aspects are joined at the hip. This hollows out the US industrial base, and hurts some regions (e.g. the Midwest) and helps others (e.g. NYC and DC).

Eventually those cumulative imbalances get so big, combined with other imbalances as well, that political realignments shift in generationally important ways. The "blue wall", referring to the northern part of the Midwest that's at the center of the rust belt and historically voted Democrat, has shifted Republican or otherwise become more mixed. The trade deficit and other imbalances have become front and center.

Establishment-type folks are going to keep being blindsided by this type of thing as long as the imbalances persist. They're going to keep pointing to one-time phenomenon, like one specific election, or one specific person, but really it's the underlying imbalance that's at the heart of it.