In the case of Karen Livadas v. Victoria Bradshaw, California Labor Commissioner (1993), the U.S Supreme Court ruled in favor of Livadas, a Safeway employee who was paid with a check that she could not immediately cash due to insufficient funds. The court found that California's law requiring immediate payment for discharged employees violated federal labor laws by interfering with collective bargaining agreements under the National Labor Relations Act (NLRA). The state argued it was protecting workers' rights to prompt payment upon termination, but this argument was rejected as it did not justify infringing on federally protected rights. This decision reinforced the supremacy of federal labor laws over conflicting state regulations and emphasized NLRA’s role in promoting free negotiation between employers and employees.

In the dissenting opinion for Karen Livadas v. Victoria Bradshaw, Justice Scalia disagreed with the majority's interpretation of federal preemption in relation to state law. He argued that California’s labor laws did not conflict with or stand as an obstacle to federal labor policy and should therefore be upheld. In his view, there was no clear evidence that Congress intended for the National Labor Relations Act (NLRA) to preempt state regulation of paychecks issued by employers involved in a labor dispute. Furthermore, he contended that even if such intent could be inferred from congressional silence on this issue, it would still not justify striking down California's law because it does not interfere significantly with any substantive right granted under NLRA but merely provides additional protection for employees' wages during disputes.