when a ruling is made by the supreme court, are they obligated to provide reasoning?
Congress sets the # of Justices, quorum, etc., but there is NO mandate, even by thier own Rules, to provide insight.
I have read a few page decisions, and then I have read 60 page decisions.
Due to the nationwide effect of such rulings, it is a guidance for the lower courts to draft detailed opinions.
I would have hated to write out those opinions myself before the advent of the typewriter or dictation machines/tape recorder where the secretary did it then.
At times, they seem to go overboard in an analysis, but they only decide about 80-100 cases a year while being Petitioned for about 3-5 thou.
To only write such as "Lower decision affirmed/vacated" would undermine the Judicial integrity of the Highest court in the land.