The Constitution isn’t “clear on this” at all. Imagine a small agency that, early in a new administration, has no officers who have yet been confirmed by the Senate. Do we really think the Constitution means no one can temporarily head the agency while the Senate does its thing? https://twitter.com/EWErickson/status/1060637268157886465 …
Shouldn't that usually be taken care of by having senate confirmed career civil servants hang around?