NEW YORK — No one could possibly be working harder right now on Broadway than Kristin Chenoweth, who is bearing the weight of a McMansion musical on her diminutive frame and making it seem like she’s hoisting nothing heavier than a few overstuffed Hermes, Prada and Chanel shopping bags.

A trouper’s trouper, Chenoweth has reunited with her “Wicked” compatriot Stephen Schwartz, who has written the score for “The Queen of Versailles.” The show, which had its Broadway opening at the St. James Theatre on Sunday, is an adaptation of Lauren Greenfield’s 2012 documentary about a family building one of the largest private homes in America in a style that blends Louis XIV with Las Vegas.

When the Great Recession of 2008 crashes the party, the Florida couple who are never satisfied despite having everything find themselves scrounging to make the mortgage payments for this unfinished (and possibly unfinishable) Orlando colossus. Not even the banks know what to do with this gargantuan white elephant.

The first half of the musical traces Jackie’s rise from a hardworking upstate New York hick to a Florida beauty pageant winner who escaped an abusive relationship with her baby daughter. Her dream of nabbing a wealthy husband comes true after she meets David Siegel (F. Murray Abraham, in vivid vulgarian resort mogul mode). He’s decades older than her but as rich as Croesus, having proudly transformed himself into the “Timeshare King.”

With David funding her every whim, Jackie discovers the joys of consumerism as her family expands along with her credit line. David adopts her first-born, Victoria (Nina White), a sulky adolescent who doesn’t appreciate her mother’s lavish ways. And the couple proceed to have six more children together before adopting Jackie’s niece, Jonquil (Tatum Grace Hopkins), a Dickensian waif who shows up with all her belongings stuffed into plastic bags.

The musical’s book, written by Lindsey Ferrentino (whose plays included the raw veteran recovery story “Ugly Lies the Bone”) deals only with Victoria and Jonquil, leaving the other kids to our imagination along with most of the pets that suffer the seesaw of lavish attention and thoughtless neglect that is the Siegel family way.

Jackie didn’t set out to build such a ludicrously gigantic residence. As she explains in the number “Because We Can,” “We just want the home of our dreams/And the house we’re in now,/Although it’s sweet,/It’s only like 26,000 square feet,/So we’re just bursting at the seams.”

This version of “The Queen of Versailles,” making the visual most of settings by scenic and video designer Dane Laffrey, that can make Mar-a-Lago seem understated, embraces the sociological fable aspect of the tale. To drive home the political point, the musical begins at the court of Louis XIV and returns to France near the end of the show after the French Revolution has bloodied up the guillotine with the powdered heads of callous aristocrats.

Jackie sees herself as a modern-day Marie Antoinette, but instead of saying “Let them eat cake” she has her driver bring back enough McDonald’s to feed an entire film crew. Chenoweth, who is as gleaming as a holiday ornament on Liberace’s Christmas tree, arrives at a canny balance of quixotic generosity and parvenu carelessness in her portrayal of a woman she refuses to lampoon.

Kristin Chenoweth and the Company of "The Queen of Versailles," many in period ball gowns in a stately room.

Kristin Chenoweth and the Company of “The Queen of Versailles.”

(Julieta Cervantes)

The second half of the musical recaps what happens when the super rich face ruin — ruin not in the sense of going hungry but of having to stop buying luxury goods in bulk. With his timeshare empire hanging in the balance, Abraham’s David transforms from Santa Claus to Ebenezer Scrooge, belligerently withdrawing into his home office like a beaten general plotting a counteroffensive and treating Jackie like a trophy wife who has lost her golden sheen.

Ferrentino extends the timeline beyond the documentary to include what happened to the family in the years since the film was released and Jackie took to the spotlight like a Real Housewife given her own spinoff. The federal bailout worked wonders for the haves, like the Siegels, while the have-nots were left to fend for themselves — casualties of questionable mortgage practices and the “more, more, more” mantra of America. But no one escapes the brutal moral accounting, not even Jackie, after she suffers a tragedy no amount of retail therapy will ever make right.

“The Queen of Versailles” has grown tighter since its tryout last summer at Boston’s Emerson Colonial Theatre, but it’s still an unwieldy operation despite the impeccable showmanship of Michael Arden’s direction. The problem isn’t the production but the musical’s shifting raison d’être.

The first act hews to the documentary in a flatly straightforward fashion. The making of the film becomes the invitation to tell Jackie’s story in the mythic terms she favors. The musical indulges her not with a smirk but with a knowing smile. It’s the culture that’s skewered rather than those who adopt its perverted values.

But not content to be a satiric case study in how the Siegel family story connects “Lifestyles of the Rich and Famous” and “Dynasty” to the shallowness and cruelty of Donald Trump’s America, the show aspires to the level of tragedy. Achieving great emotional depth, however, isn’t easy when wearing a plastic surgery mask of comedy.

Kristin Chenoweth as Jackie Siegel in "The Queen of Versailles."

Kristin Chenoweth as Jackie Siegel in “The Queen of Versailles.”

(Julieta Cervantes)

Schwartz has composed an American time capsule of Broadway pop, with as much variety as “Wicked” though with less bombast and no real standout blockbuster numbers. The score moves from the zingy send-up of “Mrs. Florida” and “The Ballad of the Timeshare King” in the first act to the more maudlin “The Book of Random,” in which vulnerable Victoria gives vent to her suffering, and “Little Houses,” in which the modest lifestyle of Jackie’s parents (played by Stephen DeRosa and Isabel Keating) is extolled in increasingly grandiose musical fashion, in the second.

Strangely, one of the show’s most captivating songs, “Pavane for a Dead Lizard,” is about a reptile that starved to death because of Victoria’s negligence. The number, a duet for Victoria and Jonquil, doesn’t make importunate emotional demands and is all the more poignant for its restraint. (White’s Victoria and Hopkins’ Jonquil come into their own here, letting down the defensive armor of their recalcitrant characters.)

Melody Butiu, who plays the Siegels’ Filipina nanny and indispensable factotum, has a readier place in our hearts for all that she has had to sacrifice to support her distant family. Her material lack exists stoically in the shadow of the family’s monstrous excess.

In “Caviar Dreams,” Jackie proclaims her “Champagne wishes” of becoming “American royalty.” Chenoweth, whose comic vibrancy breaches the fourth wall to make direct contact with the audience, relishes the humor of Jackie without poking fun of her, even when singing an operatic duet with Marie Antoinette (Cassondra James). But the material never allows Chenoweth to emotionally soar, and the fumbling final number, “This Time Next Year,” requires her to land the plane after the show’s navigation system has essentially gone blank.

“The Queen of Versailles” is designed to bring out all of Chenoweth’s Broadway shine. She never looks less than perfectly photoshopped, but the production ultimately overtaxes her strengths. New musicals are impossible dreams, and this is a whopper of a show, daunting in scale and jaw-dropping in ambition. If only Chenoweth’s dazzling star power didn’t have to do so much of the heavy lifting.