I have addressed some of these issues previously for NRO, but I provided my take on the constitutional source of broad executive power in wartime for that “other magazine” blog. It can be found here. Part of my argument is that the “prerogative” is inherent in the executive power established by the Constitution and rendered necessary by the fact that laws arising from legislative deliberation cannot foresee every exigency. For the safety of the republic, the executive must retain some latitude for action.