Tariff
A tariff is called an optimal tariff if it's set to maximize the welfare of the country imposing the tariff. It is a tariff derived by the intersection between the "trade indifference curve" of that country and the offer curve of another country. In this case, the welfare of the other country grows worse simultaneously, thus the policy is a kind of "beggar thy neighbor policy". If the offer curve of the other country is a line through the origin point, the original country is in the "condition of a small country", so any tariff worsens the welfare of the original country.
1912 United States presidential election
Before the ratification of the Sixteenth Amendment to the United States Constitution (1913), the funding of the United States government heavily relied upon tariffs. Tariffs are a direct taxation of raw materials and manufactured goods with regard to trade. This issue was key in fracturing the Republican Party. Early in his term, President Taft had promised to stand for a lower tariff bill. Protectionism was major policy of the business oriented Republican Party.