The movie erroneously mentions Hinckley's arrest in Nashville in the previous year, Reagan was there campaigning with a cabinet member mentioning that Hinkley was very close to the president. The actual potential victim was president Jimmy Carter. See more
Constitutionally, gentlemen, you have the President, the Vice President and the Secretary of State in that order, and should the President decide he wants to transfer the helm to the Vice President, he will do so. He has not done that. As of now, I am in control here, in the White House, pending return of the Vice President and in close touch with him. If something came up, I would check with him, of course.