The theme that our slide was inevitable and perhaps desirable in some respects was captured in a 2008 Fareed Zakaria book called “The Post-American World.” There and elsewhere, the argument was that the rising power of other nations and cultures would curtail America’s ability to shape events.

If we were smart, the theory went, we would limit our resistance to existential threats and otherwise work in harmony to boost the up-and-comers. Many of these so-called declinists wanted America to shrink its military even further and use the savings to fund social welfare programs like those in Europe.

Trump’s election — under the America First banner no less — provided the first jolt to the Obama-Zakaria world view. A second jolt must be how relatively fast big changes are coming, and how arguing against them could be politically perilous for Democrats.