Finally read The Old Iron Dream, which traces the strand of military authoritarianism and white male supremacy in science-fiction from John Campbell through Heinlein, Pournelle and other major names up through ~2013.
I'd known some of the broad strokes, and some of the specifics, but seeing them all tied together in a continuous thread is...enlightening. And makes it clear how people like Musk and Andreeson can look at the "genre of ideas" and only pick up on the tropes that justify their own prejudices and ambitions.