The case of Entergy Louisiana, Inc. v. Louisiana Public Service Commission et al., 2002 revolved around the issue of whether a state utility commission could require a public utility to share with its customers cost savings achieved through refinancing debt at lower interest rates. The U.S Supreme Court ruled in favor of Entergy Louisiana, stating that the Federal Power Act (FPA) preempts any such requirement by state commissions. The court held that under FPA, only the Federal Energy Regulatory Commission has jurisdiction over wholesale electricity rates and related matters like capital structures and costs associated with it including refinancing benefits or losses; therefore states cannot mandate utilities to pass on these savings to consumers.

In the dissenting opinion for Entergy Louisiana, Inc. v. Louisiana Public Service Commission et al., Justice Stevens argued that the Federal Power Act does not preempt state law regarding retail electricity rates unless there is a clear conflict between federal and state regulation. He disagreed with the majority's interpretation of Mississippi Power & Light Co. v. Mississippi ex rel Moore, asserting it did not establish a broad preemption principle but rather addressed a specific situation where state action threatened to undermine federal objectives directly related to wholesale rates in interstate commerce - which was not applicable here as per his view. Furthermore, he contended that allowing states to regulate retail prices would promote competition and benefit consumers without interfering with FERC’s ability to regulate wholesale markets effectively.