Articles of the US Constitution distribute authority to ahh rule among the political bodies of the federal gov't. The text is not convoluted. It is a list. It contains punctuation marks.

To the contrary one might confidently state, these provisions listed are definitive, or more fancifully infinitive, forms of acts. The early "modern" libertines intended this code, those authorities, to be performative, or "actualized," in the language of late modern mystics; to be "interpreted" by WHOM? without benefit of musical accompany.

The correct answer, regardless of Dowd's argument, is neither Congress nor the POTUS.

The Articles establish a few executive agents by name. These and all the rest have been created (established) and defined (vested, codified) by legislative acts in subsequent sessions of the US Congress in the English coin of the day. One may find the records --committed by the clerks of each chamber-- in physical and digital volumes of the FEDERAL REGISTER and NATIONAL ARCHIVE, if one searches, then reads and comprehends the ahh litchichure.

Statutory definitions by the US Congress very often explicitly delegate authorities to the office of POTUS and its agents (agencies: offices of agents) in order to execute (implement, regulate, direct, enforce, instiate, effect) congressional acts. A surprising amount of that cumulative work product is defective for the simple reason one provision ahhh chained to another contradicts itself. In USA detecting, not interpreting, these (=>) errors is a profession shared by lawyers, comedians, taxpayers, widows, orphans, and religious extremists.

I for one do not long for the day I awake find President Harris, Pence, or whoever from HELL, directing AG Wm. Barr on how to enforce USC --because the last session of Congress forbade the POTUS terminating the commission of any officer of the executive without the permission of a House of odious.

Diversity is the key to economic and political evolution.