Yaakov: I addressed your point in my P.S. The AG can declare the Secretary of State next in line after the Vice President. That would make Mike Pompeo the Acting President at noon on January 20, *IF* the scenario I described transpires.
CTL: There’s an Acting Attorney General. He has the same power as a sitting AG in this case. Furthermore, you are incorrect. None of the members of the cabinet, including AG, Acting AG, Secretary of State, etc stop serving in their positions on January 20 at noon, until and unless the new President or Acting President fires any of the cabinet members. Unless and until such time the outgoing administration’s cabinet legally continues to serve in their position.