This chart, contained within slides of a presentation by Robert Z. Lawrence and Lawrence Edwards promoting their new book "Rising Tide: Is Growth in Emerging Economies Good for the United States?," is quite something.
"These data suggest a cause that is common, pervasive and not closely related to the size of the trade balance," the authors conclude.
Rather, the change is due to rapid productivity growth. That is, automation is reducing the amount of labor required to produce a given amount of goods. That means that prices fall. If people respond those price changes by buying more and more of the underlying good, then sales will increase and employment may not fall. But that's not happened. Instead, people are saving money on manufactured goods and buying more services, instead. That's led to the decline in manufacturing jobs.