Mr. Thiel at the time foresaw a “grim Malthusian politics,” a period of “long-term stagnation,” leading to a “near revolutionary situation” in the U.S. It’s a view (increasingly shared by secular stagnation theorists) that he has continued to elaborate in speeches and interviews ever since.

So if Mr. Thiel this week gave himself the job of speaking for a candidate whom many of his Silicon Valley friends and peers frankly revile, one readily supposes the reasoning went like this: The Valley sees Trump as anti-trade, anti-immigration, and nothing in Mr. Thiel’s speech suggested Mr. Thiel is anti-trade, anti-immigration. But Mr. Trump is a wrecking ball at a time when Washington needs a wrecking ball. It needs a candidate whose very existence forcibly disrupts its ways and patterns.

Even Mr. Trump’s vulgarities, his reprehensible impulses (kill the innocent family members of terrorists), his dangerous suggestions (decide when the time comes whether to uphold NATO’s guarantee of the Baltics) might seem virtues, in a sense. They expand the boundaries of the sayable.