YAPP USA, an auto parts supplier, has petitioned the U.S. Supreme Court to block an administrative proceeding by the National Labor Relations Board (NLRB) scheduled to begin on Tuesday. The company is challenging the constitutionality of the NLRB's structure, arguing that the agency's operations violate the U.S. Constitution. After the Sixth Circuit Court of Appeals denied relief on Sunday, YAPP USA approached the Supreme Court on Monday, submitting the case to the Court's shadow docket. This move marks a significant escalation in the growing efforts to have courts declare the NLRB unconstitutional.