Gerry Mackie's book Democracy Defended is probably the best scholarly counter-argument to Moldbug. It goes through all the usual arguments against democracy, and offers counter-counter arguments.

You would probably want to read Stephen Holmes' The Anatomy of Antiliberalism and Albert O. Hirschman's The Rhetoric of Reaction (Amazon link) as well to put Moldbug's claims in historical and rhetorical context. Holmes' book is on the history of reactionary thought, while Hirschman's is on the rhetoric that reactionaries have used through history.

Not that I think all of Moldbug's claims are bad. The idea that there is a definite connection between American Protestants and democracy is a very strong one, I think (see this paper that was linked on Moldbug's comments section that is a much better scholarly take on Protestants and democracy).