To quote from a June 2016 post on this blog:
Trump, it turns out, has consistently argued since at least 1990 that the terms of trade between the United States and its allies unfairly favor the latter because the US subsidizes them to a vast extent by providing for free a crucial public good: regional and global security.
Yesterday, Jacob M. Schlesinger wrote in The Wall Street Journal (paywalled?):
Over several decades, the president has shifted many of his positions… and even changed parties. On trade, however, he hasn’t wavered an inch, dating back to ideas first laid out in the late 1980s.
He has repeatedly returned to the same line of thinking, adjusted for different countries and changing circumstances. Back then, it was fear of Japan’s economic might that drew his attention. Today, it’s China…
Schlesinger’s piece, although belated, deserves to be read in full, re-read and studied. The president seems voluble and volatile, but – when it comes to trade, at least – trash-talking and flip-flopping are merely tactics in the service of a deeply ingrained strategy. One is tempted to cite not only Keynes’s “defunct economist” quip but the next sentence in The General Theory, namely:
Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist. Madmen in authority, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back.
For some of his opponents, Donald Trump is a madman in authority, but it was as a practical man that he first voiced these ideas. He might have developed them independently but was unlikely to have been their first exponent: that must have been an economist, possibly predating Trump by a century or two.
“I respect economists,” Mr. Trump told the Journal. “But they’re usually wrong.”