The Prevention of Significant Deterioration (PSD) program was born 45 years ago from purposivist interpretation of the platitudinal phrase “protect and enhance” contained in the “findings and purposes” section of the 1970 Clean Air Act (CAA). The PSD program has since metastasized into big business, supporting scores of consultants, technical experts, and lawyers. The Donald Trump Administration’s push for regulatory reform has yet again raised calls for changes to the PSD program. Past reforms have provided some benefit but increased the complexity of an already byzantine program. Rather than reforming the program, a strong case can be made that the program has been rendered environmentally nugatory by the dramatic growth of the regulatory state over the past 45 years, and therefore should be repealed.