The US Constitutional law theory that allows the president of the United States with the authority to control the entire executive branch is the Unitary Law (Ch.4 PPT, slide 14)
I do not think that the president should have total control over this subject manner, in fact, I do not think they should have total control over something. According to the chapter four PowerPoint, the theory states that in Unitary Law the president controls totally and completely. In the end, we are all human, we are in the year 2022, I do not think torture such as waterboarding is a good way for interrogation. With the intervention of Congress, there is a line, a limit that is being placed, that will not let people go into extreme measures.