The original Chevron ruling was an expansion of executive branch power; it said courts should give “deference” to agencies in matters where Congress was not specific—usually in detailed findings of fact and definition of regulations, the work of the agency. Congress usually is specific about structure and governance.

The recent decision to formally overturn this precedent was a reduction in power for the executive branch, since it greatly expanded the scope of when a judge could overrule agencies. However, judges were mostly already doing this, so the big headline ruling was more like a funeral than a murder.