Asklemmy

You were correct in your initial assumption. The show The West Wing only focused on a core of close advisors, but you often got reference or hints at others that were just never featured much on screen.

Traditionally, a President has a very large staff. They have panels of experts on all kinds of different things (The President's Council of Economic Advisors, the President's Council on Physical Fitness, etc, etc). A quick (and not at all thorough) web search shows that the Executive Office of the President of the United States typically employs ~2,000 people.

The current administration is run by neophytes and morons who have little-to-no experience in government and don't really know what they're doing. They're running the government like the mob, where they value loyalty and ideological purity over experience and expertise. So they only give important jobs (like making their tariff list) to very loyal people who will do whatever the President wants. As such, the people doing the work have no clue what the fuck they're doing, so they look for shortcuts. That's why we keep seeing things like programs being cancelled which include the word "biodiversity" as a result of them just ctrl+f "diversity" and hitting delete. That's also why they turned to ChatGPT to figure out their tariffs, because they have no clue how else to do it, and have nobody with intelligence and experience to ask.