Evidence suggests that 15 tanker voyages, potentially carrying millions of barrels of oil and fuel to Hawaii, California, Puerto Rico, and the East Coast, took place under the Jones Act waiver but never showed up in the federal government’s official count.

Trump should demand that Congress codify his 2018 rule. If Congress won’t act, the administration should reissue that 2018 rule.

There might be particular situations—such as those involving legitimate threats to the integrity and defense of the United States—where expediently restricting the importation of certain goods may be a reasonable policy. Forcing American companies and consumers to endure more of the burden of costly, shortsighted, and unpopular protectionism is not one of those.