The power to commission officers, as applied in practice, does not mean that the President is under constitutional obligation to commission those whose appointments have reached that stage, but merely that it is he and no one else who has the power to commission them, and that he may do so at his discretion. Under the doctrine of Marbury v. Madison, the sealing and delivery of the commission is a purely ministerial act which has been lodged by statute with the Secretary of State, and which may be compelled by mandamus unless the appointee has been in the meantime validly removed.753 By an opinion of the Attorney General many years later, however, the President, even after he has signed a commission, still has a locus poenitentiae and may withhold it; nor is the appointee in office till he has this commission.754 This is probably the correct doctrine.755
754 12 Ops. Atty. Gen. 306 (1867).
755 It should be remembered that, for various reasons, Marbury got neither commission nor office. The case assumes, in fact, the necessity of possession of his commission by the appointee.