The underlying fact is that Trump can't unilaterally impose tariffs. NBC News:

Costco Wholesale has sued the Trump administration, asking the Court of International Trade to consider all tariffs collected under the International Emergency Economic Powers Act unlawful.

The company said in a filing Friday that it is seeking a “full refund” of all duties under the act paid as a result of President Donald Trump's executive order that imposed what he called "reciprocal" tariffs.

“Because IEEPA does not clearly authorize the President to set tariffs ... the Challenged Tariff Orders cannot stand and the defendants are not authorized to implement and collect them,” Costco's lawyer writes in the lawsuit.

MAGA can't stand it!