The Wealth of Nations by Part 4 Chapter 3 Page 65

Their interest is, in this respect, directly opposite to that of the great body of the people. As it is the interest of the freemen of a corporation to hinder the rest of the inhabitants from employing any workmen but themselves, so it is the interest of the merchants and manufacturers of every country to secure to themselves the monopoly of the home market. Hence in Great Britain, and in most other European countries, the extraordinary duties upon almost all goods imported by alien merchants. Hence the high duties and prohibitions upon all those foreign manufactures which can come into competition with our own. Hence, too, the extraordinary restraints upon the importation of almost all sorts of goods from those countries with which the balance of trade is supposed to be disadvantageous; that is, from those against whom national animosity happens to be most violently inflamed.