If “Good People” isn’t a hit for Manhattan Theater Club, there is no justice in the land. David Lindsay-Abaire pays his respects to his old South Boston neighborhood with this tough and tender play about the insurmountable class divide between those who make it out of this blue-collar Irish neighborhood and those who find themselves left behind. The scrappy characters have tremendous appeal, and the moral dilemma they grapple with — is it strength of character or just a few lucky breaks that determines a person’s fate? — holds special significance in today’s harsh economic climate.

To put a human face on this existential conundrum, Lindsay-Abaire (who took the Pulitzer Prize for drama with “Rabbit Hole”) gives us Margaret Walsh (the astonishing Frances McDormand), a middle-aged single mother with a mentally challenged daughter to support on a cashier’s salary. McDormand has an uncanny affinity for women who work hard to make a living and suck it up without complaint. As one of those exhausted but stubborn stoics, Margie walks right into her arms.

With the local factories gone south and no one in this depressed economy hiring unskilled workers, Margie panics when she loses her job at the Dollar Store. (Patrick Carroll gives a sweetheart of a perf as her baby boss.)

But her lousy job is the only thing that Margie loses. Between scribe’s warm portrayal and McDormand’s big-hearted performance, this indomitable woman manages to hang onto her dignity, her fighting spirit, and the sardonic sense of humor that the natives of this insular community use to thumb their noses at the outside world.

Saturday night bingo at the parish church where Margie takes her troubles to her friends is a great place to hear that mocking laughter bounce off the walls and to watch the Southie sisterhood in action.

Margie’s best friend Jean may look sweet, in Becky Ann Baker’s smartly underplayed perf, but this tough waitress plays dirty. Margie’s brash landlady Dottie, a foul-mouthed delight in Estelle Parsons’ raucous perf, considers herself a friend, but if Margie doesn’t pay this month’s rent, she’ll toss her out on the street without batting an eye.

Inspired helming of Daniel Sullivan (“The Merchant of Venice,” “Rabbit Hole”) keeps such a tight focus in these hilarious bingo scenes that no one can peel their eyes away from Margie and her posse. (All shrewdly dressed by David Zinn, right down to the glossy lipstick and gelled hairdo that Dottie wears with her glitzy outfits.)

The ladies may sound heartless, as they cheerfully gossip about whose husband is in jail and whose kid took an overdose. But they’re only working on the thick hide you need to survive here, and they really mean to be helpful when they advise Margie to stop being so noble and toughen up — unless she wants to end up like their old classmate Cookie McDermott, who became a bag lady and died on the street.

Dottie, that hard-nosed pragmatist, urges Margie to stuff her pride and take an assembly-line job at the Gillette factory. Canny Jean suggests more desperate measures, never mind that they’re dishonest.

When Margie takes Jean’s advice and puts the bite on an old boyfriend who recently moved back to Boston, she sets in motion the plot mechanism that will turn their awkward reunion into a bitter class war. Mike Dillon (tamed, but not emasculated, in Tate Donovan’s civilized perf) never looked back after he left home. Now a successful endocrinologist with a lovely young wife (a smart one, too, in Renee Elise Goldsberry’s confident perf) and a swell house on Chestnut Hill (a tasteful showplace, in John Lee Beatty’s mouthwatering design), he wants no reminders of the good old days growing up rough in the projects.

But Mike is no match for Margie, who is determined to get an invitation to his birthday party so she can canvass his rich friends for work. Margie may be desperate, but all she wants is a job. Mike’s need is more fundamental. He’s desperate for reassurance that he’s still “good people.”

Mike makes an earnest case for his accomplishments as a self-made man, but he’s been away from the old neighborhood so long, he’s forgotten how to fight like a street kid. Margie’s fighting style is all verbal thrust and dirty tricks: the nasty dig, the insincere compliment, and that sly maneuver of sticking the knife in and backing off with a smile and a disingenuous “Just kidding” — or, even better, “I’m just bustin’ balls.”

Lindsay-Abaire not only knows the moves, he’s at home with the pungent South Boston idiom and its hidden meanings. When Margie pulls the “lace curtain Irish” punch on Mike, she’s hitting way below the belt — accusing him of forgetting where he came from and refusing to acknowledge how much of his success he owes to other people.

The way they see it on the streets of Southie, that’s a lesson to be learned the hard way by anyone who thinks he’s “good people.”

Good People

Samuel J. Friedman Theater; 650 seats; $121 top

  • Production: A Manhattan Theater Club presentation of a play in two acts by David Lindsay-Abaire. Directed by Daniel Sullivan.
  • Crew: Sets, John Lee Beatty; costumes, David Zinn; lighting, Pat Collins; sound, Jill BC DuBoff; dialect coach, Charlotte Fleck; production stage manager, Roy Harris. Reviewed Feb. 25, 2011. Opened March 3. Running time: 2 HOURS.
  • Cast: Jean - Becky Ann Baker Stevie - Patrick Carroll Mike - Tate Donovan Kate - Renee Elise Goldsberry Margaret - Frances McDormand Dottie - Estelle Parsons