One of the barriers to executive action is the formal structure of our legal system. The executive has power to intervene in criminal and law enforcement actions, but these cases are heard and orders come from judges in civil courts. Civil courts are designed to handle property - money matters, generally, not the taking of life.
Legislators have demonstrated over the years that they are, for the most part, a spineless lot. But they could divest civil courts of jurisdiction to hear and decide cases involving living wills or the withholding of medical care when that wihholding becomes the primary agent of death.
SO make these cases a matter for criminal courts, and then perhaps the executive could set a precedent for intervening. Our country is in DESPERATE need of a leader with the will to truly lead and stand tall against courruption, ala Reagan or TH. Roosevelt, or Lincoln.