Is the presidential succession law constitutional?

In this essay, Akhil and Vikram Amar attack the constitutionality of the current presidential succession statute, which places the Speaker of the House and the Senate President pro tempore first and second in line, respectively, if there is neither a President nor a Vice President. Relying on the words of the Framers, the text and logic of the Constitution, and various practical and ethical concerns, the Amars conclude that federal legislators are not ''Officers'' under the Succession Clause and thus ineligible for the line ofsuccession. Finally, the Amars suggest that an updated succession statute should provide for a prompt national election after succession, and should iron out various other wrinkles in the current succession statute.