Musk is definitely an idiot when it comes to a lot of technical knowledge about the fields he pretends to be knowledgable in (see that twitter interview where he suggested to “rewrite the code”). But he is not stupid when it comes to throwing around money to manipulate people, just plain evil.
Also to suggest that this is all from the genius of Musk, Trump and co. alone is a stretch. Years of Republican propaganda, lies, gerrymandering, erosion of ethics and laws, democrats sitting idly by, as well as building up an army of news organizations and influencers did contribute a lot to their rise to power. There are definitely some cunning people on the Republican side, and populists like Trump now profit from the environment they created.