Chevron Deference after Mayo

The authors provide the background to the issues decided by the Supreme Court in Mayo regarding the deference the courts should grant to Treasury regulations. The implications are broad, since the deference issue determines whether the administration or the judiciary's opinion should prevail. The paper then discusses the impact of Mayo on the Chevron deference, and how the two-step approach should be applied to regulations and other Treasury pronouncements. Finally, the paper will address the role of legislative history and the Chenery and hard look doctrines within Chevron's two steps.