MAGApedes are in a cult, read Snapping by Conway on how different kinds of cult deprogramming work.
Libertarians like books, especially stuff that isn't explicitly aligned.
Russell Kirk's Conservative Mind redpills on why Reactionary thought reacted to Classical Liberalism in Jacobin revolution.
Dugin's Fourth Political Theory and Troy Southgate's Tradition And Revolution are good places to get at Anarchist oriented people.
Feudal Society i&ii by Bloch and Gies' Cathedral, Forge And Waterwheel are great for deprogramming Hollywood/Liberal memes about how "awful" and "unfree" the feudal system was, and are purely History books.
These are good books (4PT, T&R, Feudalism books) for redpilling anprims too.
(All these are on libgen and b-ok in multiple formats; recommend Fbreader and/or Ebookdroid for the ebook-challenged)