This term's Supreme Court decisions have completely remade administrative law, both by eliminating Chevron deference and by effectively eliminating the Administrative Procedures Act's statute of limitations. In Loper Bright Enterprises v. Raimondo, the Court held that as a constitutional matter federal courts could not give deference to federal agencies' interpretations of ambiguous statutes. And then the Court opened the door to APA challenges to virtually every existing federal regulation, no matter how old, with Corner Post Inc. v. Board of Governors of the Federal Reserve System, a statutory ruling that the APA's six-year statute of limitations runs from the date a plaintiff is allegedly injured by the regulation, rather than from the date of the regulation's finalization. That means that a business that is incorporated tomorrow has at least six years to challenge any regulation that affects it, and maybe more depending on when it is affected. In other words even New Deal or Progressive era regulations could be challenged tomorrow and there would be no deference to the agency's long-standing interpretation of the statute authorizing the regulations. I pity my colleagues who teach admin law--their course lost at least a credit hour's worth of material. Maybe they'll decide to take up commercial law....
These decisions are, taken together, a major rolling back of the administrative state. But these decisions will affect different agencies differently, and the Court's rulings may have some unintended consequences. To wit, many federal agencies have both rulemaking and enforcement powers. In some instances, enforcement is dependent on rulemaking, as the agency lacks a general statutory prohibition to enforce, but can only enforce its particular rules. The EPA is (I think) an example of this type of agency. It doesn't have a general statutory prohibition of "don't pollute." OSHA and the FDA and NLRB and Dept. of Commerce. For agencies in this category, Loper Bright Enterprises and Corner Post clip not only the agencies' rulemaking power, but also their enforcement power, because they will have to defend the rules they are enforcing.
In other instances, however, the enforcement powers are independent of rulemaking, as there is a broad statutory prohibition that the agency can enforce without rules. This is where federal financial regulators sit. In these cases, Loper Bright Enterprises and Corner Post will have a hydraulic effect: agencies are going to do what they're going to do, so if they can't do it through rulemaking, they'll do it through enforcement and supervision. In other words, what the Supreme Court did was to supercharge regulation by enforcement in the financial regulatory space.