The first episode, directed by John Ridley (“American Crime”), quickly and elegantly sketches out the show’s themes. In a direct homage to the show’s namesake, “The Godfather,” we see Johnson at the party alternately dispensing benevolent patronage and receiving quiet updates about weapons caches and the activities of “the Italians.” He sneaks out and shares an ice cream with his daughter but immediately gets pulled back in, called away to deal with a violent situation on 146th Street.

His new nemesis is Gigante, and one main strand of the plot is their escalating battle, carried out partly with guns but largely through insult-laden face-offs, in which Whitaker’s reserve plays off D’Onofrio’s eccentric volatility.

More space is taken up, though, with the uncomfortable question of Johnson’s role in the community, and his twinges of guilt over the damage done by the heroin he peddles. The story is arranged so that he bounces between Powell, who treats him with breezy condescension, and Malcolm X, who confronts him with scolding righteousness. Both decry the effects of his drugs, but both are happy to use him for their own political or personal gain. And Johnson conducts his business in a kind of dark parallel to theirs, organizing the community in his own way and engaging in what’s essentially a race war with Gigante and his crew.

It’s a promising setup, but the show doesn’t build on it after the opening episode. The story starts to veer off into tangents that are melodramatic (a fairly insipid Romeo and Juliet subplot involving Gigante’s daughter), distractingly implausible (an episode built around attempts to fix a Cassius Clay fight) or both (a family member of Johnson’s caught up in drugs and prostitution).

Each of these plot strands tries to tie together all of show’s big issues — race, drugs, family, the radical ferment of the ’60s — and the effort is as exhausting for the audience as it must have been for the writers. (The show’s creators, Chris Brancato and Paul Eckstein of “Narcos,” wrote the first four episodes.) The tone tends to be restrained and talky, but there are regular doses of more sensationalistic material, like a recurring blaxploitation-style character named Big Dick Buster who has a distinctive way of getting information out of male captives.