Former President Donald Trump has an excellent chance of winning the presidential election. If he wins, it won’t be because he knows anything about economics. The latest example of Trump’s proclivity for spouting economic nonsense occurred last week when he said that he was thinking about replacing the federal income tax with a policy of national tariffs.

Trump claims he would raise revenues by imposing very high tariffs on the goods and services produced overseas but consumed in the United States. Trump hates the structural trade deficit that the U.S. has incurred since the mid-1970s. But reducing the trade deficit through tariffs is terrible economic policy.