The share of clothes sold in the U.S. that is imported rose from about 20% in 1990 to 60% today.  It is one of the sectors of most dependent on imports. Close to half of textile and clothing imports are from China. The workforce in textiles declined from 700,000 in 1990 to about 200,000 today. (Go here.) Employment at the 200,000 level has been stable since the early 2010s. today there are about 270,000 in the labor force.

The Trump tariffs are designed to bring back production to the U.S.  Where will the workers come from?

Nationwide, about one third of textile and clothing production workers are foreign born. On third of these workers are unauthorized. (Go here.) Half or more of industry workers in New York City and in California are foreign born, many of them unauthorized. (Go here.) The domestic apparel industry is heavily concentrated in California, where foreign-born workers are the majority of the industry workforce.  It is very likely that increasing the production of clothes in the U.S. will depend on the availability of more foreign-born workers.