I didn't believe in the "American Fiction" story for a moment, but just about everything star Jeffrey Wright does is utterly convincing.

Satire is tricky, anyway, and "American Fiction" has a wisp of a great idea, but it muddies the waters with too many subplots and attempts to make its supposedly cranky protagonist more appealing to viewers.

Here's that idea: The novels of learned Prof. Thelonious Ellison (Wright) are rejected by readers, but he notices other learned people sell gazillions of copies of books that seem to confirm stereotypes about Black people, including current bestseller "We's Lives in Da Ghetto," by a writer played by Issa Rae. So he angrily crafts a similar book, under a pseudonym, and it becomes an instant hit, forcing him to pose as the streetwise thug he decidedly isn't.

That could work, in the way satires "The Big Short" and "Wag the Dog" did, if writer/director Cord Jefferson stuck to his guns. But it's immediately clear that Ellison is not a crank but a softy, which makes the satire squishy at its core. That's why "American Fiction" feels like two wildly different movies, one that takes big stabs at human foibles (Sterling K. Brown, with requisite swimsuit scene, is also on board as Ellison's messed-up brother and Adam Brody plays a dim-witted publisher) and one that features Ellison falling in love with his mom's extremely forgiving neighbor (Erika Alexander).

Even though they don't seem to fit in "American Fiction," those last scenes are the best in the movie. Wright and Alexander have a relaxed, sexy chemistry that makes us feel like their characters are in their own little world, almost as if the two actors resolved to ignore the insanity going on around them and create something real.

Alexander brings warmth and intelligence to her underwritten character, and Wright, who has had far too few leading roles since his 1996 breakthrough in "Basquiat" (he's also great in the current "Rustin") is electrifying. His Ellison is angry, compassionate, sensual, flip, caring and brilliant — all at the same time, which is why he's been touted as an Oscar contender.

Wright's sensitivity holds the movie together through some rough spots and helps "Fiction" begin to hit its targets in the closing scenes, when it brings more nuance to the discussion around writing about Black characters. In an argument with another Black novelist, Ellison argues that he shouldn't be expected to confine himself to writing about slavery or gangsters (any more than "American Fiction" should be required to depict them): "I'm not saying these things aren't real. But we're also more than this."

"American Fiction" gets more focused, less broadly comic, in those discussions — which also feel true to the novel on which it's based, Percival Everett's "Erasure" (published by Minneapolis' Graywolf Press). "Fiction" and Ellison, it turns out, do have interesting things to say about the dilemma of fiction writers, who shouldn't be confined to writing about their own lives but who risk criticism when they step outside that territory.

The movie gets to a provocative place, ultimately. And it's lucky to have Wright — a nominee for a Golden Globe for best actor in a musical or comedy (the film is also nominated for best musical or comedy) — anchoring it until it finally arrives there.

'American Fiction' *** out of 4 stars Rated: R for strong language and drug use.