Paul Hibbard’s review published on Letterboxd:
Fred Hampton is a man full of convictions, but less so full of complexity. William O'Neal, however, played magnificently by Lakeith Stanfield, is nothing but conflict and complexity. Judas and the Black Messiah, though powerful, is just short of being great by the director's insistence or giving both men almost equal focus, causing a frustration for me at least as a viewer when O'Neal wasn't on screen. Every political statement could have been made through O'Neal's character, he being manipulated and used by the system, while Hamptom could have been through his perspective at all times.
That said, what's good in this is really good. At one moment, Jesse Plemmons character agent Roy Mitchell tells O'Neal that the klan and panthers are one side of a coin, then spends the rest of the movie proving he and the fbi are completely in line with the klan.