Mercantilism probably makes some sense if you are operating a state capitalistic system like the Chinese. Every export business is, in a sense, an arm of the state, which seeks to accumulate and distribute assets in a way to maximize public gratitude and stability.
America is a different story. Our country does not trade with China; our people and companies do business with their businesses. Does it make sense to say that I am “losing at trade” if I buy a Chinese-made TV at a really good price? Similarly, are American construction and manufacturing companies “losing” if the Chinese are selling steel at remarkably low prices? Clearly, no.
The bottom line with trade is that it is intended to benefit everyone; it is not a zero-sum game. Focusing exclusively on the deficit in traded manufactured goods is, therefore, a warped way of looking at the situation, particularly since Americans frequently add much of the value to “Chinese” products in the first place.