The author support the claim that the President has an "enlarging scope of responsibilities" is explained below in details.
Explanation:
The Constitution explicitly authorizes the president the authority to approve or veto the law, order the armed troops, ask for the drafted evaluation of their Cabinet, assemble or dismiss Congress, grant pardons and forgiveness, and receive ambassadors. The President is accountable for accomplishing and administering the laws written by Congress and, to that end, designates the heads of the national bureaus, including the Cabinet.
