James Ellroy begins American Tabloid with a monologue that comes straight out of his mouth. On first reading, it seems like mood building and nothing more. But upon rereading lines like "America was never innocent" and "It's time to embrace bad men" after finishing the book, the monologue seems more like an explicit defense of his work and writing style.
If you come to American Tabloid expecting flowery, beautiful prose, you will be sorely disappointed. Likewise, if you come expecting some morally good characters or at least a moral message, an implicit judgment of his characters' monstrous actions, you will be disappointed. There could be possibly no better assessment of Ellroy as a writer than that he 'embraces' bad men. The entire story is written from the perspective of three evil people, and the entire world that revolves around them is corrupted, too. Nobody has clean hands. The only thing that matters is who's smart and strong enough to win.
Love this novel. I think of it almost as a macro-scale horror story. Almost mind-boggling that it hasn't been adapted to film, but Ellroy's work has proven difficult in that regard. (LA Confidential doesn't count, since it's basically a different story.) I'll disagree on one point though: Ellroy's prose. It's unpleasant, but very intentionally so, and knocking it for unpleasantness is a little like knocking the story for the same. To me, he's an incredible stylist, and I say that as someone who also finds it exhausting sometimes. The sequels aren't half as tight as American Tabloid, but I'd still recommend them. Amazing protagonists throughout, Wayne Tedrow Jr. is literally me.