For every American employed making steel or aluminum in 2018, 36 were employed by firms that used steel or aluminum as inputs. By raising the prices of these metals, Mr. Trump’s tariffs destroyed far more manufacturing jobs than they created. Overall manufacturing employment fell in each of the four quarters of 2019 and in the first quarter of 2020, leaving the pre-pandemic level of manufacturing employment lower than when Mr. Trump took office.
The higher cost for steel and aluminum and Chinese component parts produced by Mr. Trump’s tariffs, combined with foreign retaliation, reduced the demand for American exports. As a result, the annual rate of growth in manufacturing output fell, turning negative in the fourth quarter of 2018. By the first quarter of 2019 it reached a post-Great Recession low of negative 5.3%. Manufacturing output growth continued to fall until its post-lockdown bump in the second half of 2020. Under Mr. Trump’s protectionist policy, total manufacturing output was 2% lower by the start of the pandemic than it was when he raised tariffs.
Protectionism even hurt manufacturing in the states it was supposed to help. According to the Bureau of Labor Statistics, manufacturing employment in Michigan, Pennsylvania and Wisconsin, which increased in 2017 and 2018, started to fall in 2019 as the trade war intensified. Mr. Trump lost all those states in 2020.