Nearly every large American retailer is in a similar situation: 98 percent of the footwear bought by Americans is made overseas, and 97 percent of clothing sold in the United States is produced in other countries.

“This migration to Asia has been happening since the ’60s,” Mr. Boyle said. “And so everybody who made investments in machines to make fabric or extreme, you know, plastics to make nylon or any kind of textile products — all those investments have been in Asia. All the technology.”

Along with the factories, the manufacturing expertise has moved overseas.

“It’s one thing to design a shirt like you’re wearing,” Mr. Boyle said. “You can sketch that out on a piece of paper. But to make it fit somebody, that’s a technical expertise in tailoring that doesn’t exist here anymore. You could come up with some stuff that nobody could wear.”

Mr. Boyle conceded that if Mr. Trump does hit China with more tariffs — and Columbia is not immediately able to find a way around them — the company will have no choice but to charge more, despite its long expertise in navigating trade winds.