Subject: Re: SCOTUS today
A bad decision. You simply cannot administer the vast and complex modern US government without delegating rule-making to agencies. The laws are passed by Congress, but they are in no way capable of handling all the detailed rule making necessary to implement those laws.

The decision does not prohibit agencies from engaging in rule-making. It undoes the presumption of correctness that applies to their interpretation of statutes. Chevron said that where statutes are ambiguous, courts should defer to what the agencies thought those statutes meant, rather than trying to resolve the ambiguity independently. Rule-making wasn't at issue, except to the extent that rules are often the subject of these types of disputes.