Just Mercy is successful thanks to good intentions and excellent performances. It's fairly straightforward as a courtroom drama, and there's nothing wrong with that, although it means the movie lacks a certain spark. The story of an African-American wrongly placed on death row is one that needs to be told, one based on events from many years ago yet still relevant today. If Just Mercy doesn't rise above its generic roots, it nonetheless uses genre to effectively tell its story.
Just Mercy is helped immensely by its cast. The two primary supporting actors are former Oscar winners, Brie Larson and Jamie Foxx. Larson is a favorite of mine, and she's good here, but her character feels as if the studio wanted a white face for "balance". (It's worth nothing, though, that as far as I can tell, Just Mercy sticks closer to the actual facts than many such movies.) Foxx is terrific ... he has the type of role that has Oscar written all over it, and it is puzzling that he did not get a nomination. (The same could be said for the movie as a whole. It is mainstream enough, good enough, and contemporary enough that it got lots of Oscar buzz, but it ended up with no nominations.) And Michael B. Jordan is apparently incapable of a bad performance. His quiet intensity makes Foxx's more energetic acting look even better.
It's an odd coincidence, but all three of these actors first came to my attention on television shows: United States of Tara for Larson, In Living Color for Foxx, and most notably, Jordan in The Wire.
Just Mercy is good, not great, but often, good is good enough.