“SHOW ME A HERO”, a new series on HBO, starts with a victory speech: an ominous sign. When a first episode ends in triumph, the only way ahead is down. The year is 1987, and 28-year-old Nick Wasicsko, an ex-cop, has just become the youngest mayor of Yonkers, a New York suburb that was then mostly working-class and white. Wasicsko won because he promised to appeal a federal court order requiring Yonkers to build subsidised housing on its richer, whiter east side, to counteract the concentration of poverty in its mostly black west.

As he speaks, a telephone ringing in the background grows gradually louder. The scene cuts to the next day, when the new mayor takes a call from the city’s lawyers. There are no grounds for appeal, they tell him. Wasicsko is disappointed, but resigned. Now it’s time to follow the law and build the houses, he reasons: nobody can blame me for that, right?

Over the next five episodes, the ramifications of Wasicsko’s decision play out in two worlds. In the world of city politics he is, of course, roundly blamed: it costs him his career (saying this gives away nothing: this is a true story, ably told by Lisa Belkin in her book of the same name, and adapted by David Simon, creator of “The Wire”, and his fellow writer William Zorzi). He appeals to his fellow citizens’ pragmatism: for every day Yonkers fails to come up with a workable plan to build the houses, the court will hold the city in contempt, with fines doubling daily from $100. He also appeals for support from New York’s governor and senior senator—Mario Cuomo and Daniel Patrick Moynihan, titans of 20th-century American politics and liberal icons. But they dodge his calls, unwilling to alienate their white working-class supporters. He goes from being a rising star to getting spat on in front of the television cameras.

To the show’s credit, it does not turn Wasicsko into a white saviour, though at times he seems eager to be one. Oscar Isaac plays him perfectly: needy, ambitious, desperate to be loved and self-obsessed (a politician, in other words), but basically decent and a bit out of his depth. After just one term he loses the mayoralty to Hank Spallone, a charismatic demagogue who promises to “fight” the housing decision, but never says quite how. Alfred Molina plays Spallone with slicked-back hair and an alligator grin, forever chewing on a toothpick.

The series also shows the lives of people who are stuck in Yonkers’s high-rise, crime-ridden housing projects. Initially, these stories seem peripheral: in the first episode viewers are hurled into the deep end of municipal politics. But as aficionados of “The Wire” will know, Messrs Simon and Zorzi do not create peripheral characters. Everyone matters. And as the series progresses their arcs neatly tie in to the main narrative, and it becomes their story.

Still, people outside Yonkers may wonder why they should spend six hours of their lives caring about any of this. There are two reasons. First, because the questions it raises remain painfully topical. How does a politics based on faith that people will do the right thing defend itself against demagoguery? America has done away with legal segregation; how to do away with its legacies? How should people overcome the fear of their fellow citizens who happen to look different than they do?

And second, because as drama “Show Me a Hero” excels. Younger viewers may find this hard to believe, but once upon a time American studios made films for adults, with nary a dinosaur, superhero or hunger game in sight. Directors such as Elia Kazan, Sidney Lumet and Spike Lee dealt with serious moral questions, and made urban realism riveting. Messrs Simon and Zorzi are their successors, but their work is richer, more sophisticated—and better.