US seaports handled the equivalent of 451,000 40-foot containers of goods from China in December, a year-over-year increase of 14.5%.

The migration of manufacturing to Mexico could undermine Trump’s promise to voters that ratcheting up tariffs on China would incentivize companies to bring production back to the U.S and give American companies a more even playing field.

American buyers rushed to stockpile Chinese goods before Donald Trump returns to the White House with a threat to impose tariffs of between 10 and 60 percent.