“Broken City,” which opens in theaters Friday, is a film about tough guys, in a tough city, navigating one its dirtiest sectors: mayoral politics. Russell Crowe, who is not always successful at masking his Australian accent with an inconsistent New York one, is Nicholas Hostetler, the incumbent mayor of the Big Apple. Like most mayors in dramatic thrillers, he’s as crooked as a Palm Beach County voting machine, circa 2000. And he drinks scotch in the morning, like an exile from “Mad Men.”

Losing ground in his re-election campaign to a liberal firebrand (Barry Pepper), Hostetler enlists the services of unscrupulous ex-cop turned private investigator Billy Taggart (Mark Wahlberg) to track his wife’s every move, suspecting that she is having an affair with another man.

There are shades of “Vertigo” in this premise, but Taggart is a focused, take-no-crap bruiser, never growing transfixed to his subject like Hitchcock’s Scotty. And anyway, “Broken City” is not about voyeurism and obsession; this is a film about corruption, plain and simple, and there is more to Hostetler’s wife’s (Catherine Zeta-Jones, whose talents are under-utilized) secret meetings with a confidante than a mere affair.

Yet the movie takes its time to reach this plain and simple conclusion, losing itself in a convoluted labyrinth of secrets and lies, from possible infidelity to the clandestine actions of a campaign managers to a supposedly closed seven-year-old murder case that will have an impact later on. Then there’s this business with a low-income housing project the mayor is planning to controversially redevelop, which is one of many threads that may remind viewers of the Starz series “Boss.” And frankly, Crowe’s Hostetler is lovably milquetoast compared to the brutal politico of that series, Kelsey Grammar’s Tom Kane; it’s hard to top the gold standard of mayoral malfeasance.

Overplotted as it may be, Brian Tucker’s screenplay shows a savvy understanding of political speech and dialectics, and it includes a riveting debate between Crowe and Pepper that feels tailored to the income inequality of our time. Moreover, I admired the movie’s refusal to allow morality to enter what the filmmakers convey is an amoral world, rotten and unredeemable.

As protagonists go, there can’t be less of a saint than Billy Taggart, an alcoholic who lost his badge thanks to an unlawful revenge killing and engages in the guttersnipe work of snooping on people’s spouses, often leaving his subjects bloody and bruised, if they attempt to confront him. In the movie’s grand scheme of things, this antihero is simply the lesser of many, many evils – an embodiment of the sentiment that there’s no crying in politics, there are no nice guys in government, and to get ahead, you must fight fire with more fire. Sounds pretty accurate, doesn’t it?