As a co-equal branch of government, the legislature has the right to delegate its rule-making authority as it deems fit and provide oversight to whatever individual or body they delegate to - or create said body through passage of a new law.
Indeed, but there are limits to that delegated authority as has been ruled by SCOTUS and particularly when the laws governing that delegation of authority are badly written.
When such laws/doctrine have been widely accepted as settled for many decades, it becomes arguable that it's an instance of judicial activism by SCOTUS, and possibly a power grab to pick and choose on a case-by-case basis which laws (and rule-making bodies) SCOTUS likes for non-legal, partisan reasons. Such an arrangement would make the legislature subservient to the judiciary, rather than co-equal.
