During the summer of 2017, fifteen former leaders of the White House Council of Economic Advisors signed a letter to President Trump urging him not to place tariffs on imports of steel into the United States. The letter notes that "Among us are Republicans and Democrats alike, and we have disagreements on a number of policy issues. But on some policies, there is near-universal agreement. One such issue is the harm of imposing tariffs on steel imports." Tariffs are taxes imposed by the government on imports. Those who endorse tariffs and other barriers to free international trade believe that such barriers protect domestic industries and the jobs of their employees.

Questions: (a) Why do many economists, including those who have served for both Republican and Democratic administrations, support free trade policies and oppose tariffs and trade barriers even if these barriers are designed to protect domestic workers from losing their jobs? (b) What types of jobs would be most vulnerable to job losses due to competition from imports?