To speak exactly, therefore, the effect of a protective tariff is to increase the amount of labor for which certain commodities will exchange. Hence it reduces the value of labor just as it increases the value of commodities.
DBx: Contrary to protectionists’ core belief, workers on the whole cannot be made richer by decreasing the amount of goods and services available for workers to purchase and consume. This reality is unavoidable even though decreasing the amount of goods and services available for workers as a whole to consume raises the real wages (and, hence, the ability to consume) of some subset of workers.
Show me a protectionist who believes that tariffs make the domestic population on the whole materially wealthier (that is, nearly any protectionist) and I’ll show you someone who commits the fallacy of composition.