In the United States v. Haggar Apparel Company case of 1998, the Supreme Court ruled in favor of the U.S government against Haggar Apparel Co., a clothing manufacturer that had been importing partially assembled pants from Mexico to finish assembly in Texas. The company claimed it was entitled to duty-free treatment under Harmonized Tariff Schedule (HTS) provisions for products "assembled" in foreign countries but "completed" domestically. However, Customs denied this claim and imposed duties on these imports arguing that they were not merely completed but substantially manufactured abroad which did not qualify them for HTS benefits. The court held that Chevron deference applies to regulations issued by customs authorities interpreting tariff schedules because Congress has explicitly left gaps for agencies like Customs to fill with reasonable interpretations through rulemaking procedures. Therefore, if such agency's interpretation is reasonable then courts must accept it even if they might have reached a different conclusion independently. This decision established an important precedent regarding judicial review of administrative decisions related to trade laws and affirmed executive branch authority over import policy.

In the dissenting opinion for United States v. Haggar Apparel Company, Justice Scalia argued that the majority's decision to grant Chevron deference to a Customs Service regulation was incorrect. He contended that Congress had not delegated authority to the Customs Service in this matter and therefore its interpretation of "assembly" should not be given any special weight by courts reviewing it. Instead, he believed that courts should interpret laws independently without deferring to agency interpretations unless explicitly instructed otherwise by Congress. Furthermore, he criticized the majority's broad application of Chevron deference as an abdication of judicial responsibility and warned against expanding executive power at the expense of judicial independence.