The doctor analogy is completely inappropriate. The main job of the chief executive of the country is to act as an executive. The President doesn't create laws, and the President doesn't interpret laws. The President will sign or veto legislation sent to him, will put together a cabinet that will handle the nitty gritty of governance, will appoint federal judges, and will provide direction via the bully pulpit. That's it.
The President also has broad executive authority to act autonomously, is commander-in-chief of the military, and conducts foreign relations (along with the Secretary of State, who in the "unitary theory" of the Executive, serves at the pleasure of the President).
And if Trump, who shows little regard or even understanding of our system of government and Constitution, oversteps his legal authority, who is going to stop him? Do you think, what, Congress or the DoJ or the Supreme Court is going to send federal marshals to seize him in some kind of coup? No. His actions will have to be legally challenged by a damaged party and go through the entire judicial system - a process that could take months - or he would need to be impeached and convicted - a process which could take months - all while Trump continues to hold the reins of power.
There is a difference between
authority and
power. There are a lot of things the President doesn't have the legal authority to do, but has the power to do nonetheless.
