Here’s today’s brief history lesson. The Roman emperors preferred to respond to specific circumstances by deciding cases on an individual basis without getting a law passed. This was to maintain the fiction that the Senate was still in charge, and only the Senate could pass laws.
Pliny the Younger, for example, wrote scads of letters to Trajan, who decided the case, nor was this unusual. These letters were used as the basis of other decisions by the courts, creating an incredible volume of case law that in the 7th century Justinian got around to codifying.
In this way it was possible to create law without legislating. In the U.S., the Supreme Court caught on early to this, and began creating law by judicial action through the expansion of judicial review.
Now it appears that the Executive is catching up. Pretty soon Congress, which is supposed to be supreme over the other two branches since it represents the people, will become as redundant as the Roman Senate on which it was modeled.