What’s Trump’s authority for superseding the AG Succession statute? He’s undoubtedly invoking the Vacancies Reform Act of 1998 (VRA), which provides (5 U.S.C. § 3345(a)(3)) that the President “may direct an officer or employee of [an] Executive agency to perform the functions and duties of [a] vacant office,” provided that the officer or employee has served, for at least 90 days during the year before the vacancy, in a position for which the pay is at least the level of GS-15—a criterion that Matthew Whitaker satisfies.
The Department of Justice’s formal view is that the VRA provides the President with an alternative authority, in addition to the AG Succession Act, to designate who shall perform the AG’s functions and duties during a vacancy in the office. Thus, for example, when AG Alberto Gonzales resigned in 2007, President George W. Bush named the Assistant Attorney General for the Civil Division, Peter Keisler, to be the Acting Attorney General, when the AG Succession Order in effect at the time, issued pursuant to the AG Succession Act, would have assigned those functions to the Solicitor General, then Paul Clement.