You've done a nice job of articulating the arc of growing inequality but missed one of it's main catalysts. One which, unfortunately, doesn't lend itself well to conventional solutions like raising the minimum wage.

The disruptive impact that technology has had on the economy has stimulated a paradigm shift in how income is distributed. Increasingly human labour is being replaced by machine labour, artificial intelligence and lower cost geographically dispersed human labour in places like China. The resulting increase in profits have moved in great measure to the owners of capital.

In such a climate, raising minimum wages will only lead to a faster shift to machine labour as corporations follow their natural course of reducing costs in order to maximize profit.

Economic policy that relies on conventional concepts of how the supply / demand curve of human labour functions is destined to fail. Time for a new paradigm. Personally, I believe some variation on universal basic income is in order.