There's a novel like this...

Oh yes, Stranger in a Strange Land. I am pleased to find that this Joan Quigley character "was called on by First Lady Nancy Reagan in 1981", twenty years after Heinlein's book was published.

> [Alice Douglas][1] — (sometimes called "Agnes"), wife of Joe Douglas. As the First Lady, she controls her husband, making major economic, political, and staffing decisions. She frequently consults an astrologer, Becky Vesant

[1]: https://en.wikipedia.org/wiki/Stranger_in_a_Strange_Land#Cha...

edit: Oh, I see other people have posted about this already. Well that's the character's name, anyway.

This makes me realize that there is probably a lot more that I missed in "Stranger in a Strange Land", just by virtue of my age and not having been born in the USA.

"Stranger" was published in 1961, 20 years before Reagan, but still has many good insights on social and political patterns in the US. For a more dated, but more detailed and insightful view by a stranger, try: https://en.wikipedia.org/wiki/Democracy_in_America

Also see Philip K Dick's books from the 50's and 60's, which include actors as American Presidents.

Huh, I didn't realize that. That's oddly prescient, then.