One of the most polarizing films at this year’s Toronto International Film Festival — at least within certain critical circles — was Jonathan Demme’s Rachel Getting Married. It’s ironic that a film so obviously intended in a spirit of reconciliation could prove so divisive.

The basic premise recalls Margot at the Wedding: the return of a prodigal daughter (Anne Hathaway) to the familial fold on the occasion of a backyard wedding. But where Noah Baumbach’s acrid anti-comedy mocked the union at its centre and revelled in its characters’ crippling dysfunction, Demme’s film explores the possibilities of forgiveness for each of its damaged principals, and lavishes extended attention on the nuptials.

It’s this last point which proved particularly sticky for some of the film’s detractors, who groused that the explicitly multicultural aspects of the ceremony — a clan of Connecticut WASPs whose daughter is marrying a black musician (played by TV on the Radio frontman Tunde Adibimpe) have an Indian-themed wedding with appearances by a Louisiana jazz band — amounted to transparent, lefty-utopian proselytizing. And so they reduced Rachel to a calculated, election-year Benetton ad, complete with Robyn Hitchcock singing about being “up to [his] neck in love.”

“It’s a fluke,” Demme says, during a roundtable interview at TIFF, of his film’s potential political implications. “I hope that the audience’s energies don’t get sucked into [that reading] because there’s no such intention. The diversity factor, to me, is moving, but where I live, in New York, it’s just a fact of life. I think that our film is on the money, demographically speaking. It’s not fabricated.

“On the other hand,” he continues, “I guess it does offer positive reinforcement of the idea that people can get together and get along. We all just watched the Democratic Convention, with 80,000 people there for Obama’s speech in that stadium, and we all sort of thought: ‘Hey… that’s like our movie!’”

In other words: the director can’t quite make up his mind about his own work. That’s okay, because what’s onscreen represents Demme’s loosest, most appealing fiction filmmaking since the late 1980s, despite the rather schematic design of Jenny Lumet’s screenplay. For instance, it’s obvious that Hathaway’s chain-smoking black sheep Kym, barely five minutes out of the rehab clinic and en route in the family car to the wedding rehearsal dinner for her sister Rachel (Rosemarie DeWitt), is going to wreak all manner of havoc on the weekend’s proceedings. It’s equally clear that her toxically narcissistic behavior masks some deeply buried pain that will be excavated by the end of the film.

These narrative beats are drowned out by the spontaneity of the performances, including superb work by Bill Irwin as Rachel and Kym’s self-effacing dad. There’s also a swirling energy to the filmmaking, Demme and cinematographer Declan Quinn having shot each scene documentary-­­style in long takes with multiple cameras.

“His eye is incredible,” Demme says of Quinn, with whom he worked on the recent documentary Jimmy Carter: Man From Plains. “We didn’t rehearse and we didn’t design shots. We just went for it.”

So too, it seems, did Hathaway, whose work is good enough to position her as a potentially major actor rather than “that girl from The Princess Diaries.”

“I didn’t know that this existed,” says Hathaway, 26. “I didn’t know there was such a thing as the Venice Film Festival or the Toronto International Film Festival. I didn’t know that there were people like Jonathan Demme. And it’s cool, because I feel like I’m getting back to what I wanted when I was a young girl: to be a storyteller. Now that those terms are clearly defined, I feel like I can begin.”

Hathaway may be delighted to have discovered Demme, but those with a long-time stake in his career will probably come away from Rachel Getting Married with a different kind of satisfaction: the feeling that a filmmaker who had recently been floundering has rediscovered his gracious sensibility. The presence in the cast of so many of the director’s friends and long-time collaborators — from “Sister” Carol East and Fab Five Freddy to Paul Lazar to Demme’s daughter Josephine — gives the film an interesting double-exposure effect, as if one family reunion was being superimposed on top of another. In which case, it’s perfect that there’s a shot late in the film of an old man shooting the wedding on a digital video camera. It’s not hard to miss but if you do notice, the man is easy to recognize as Demme’s mentor Roger Corman.

“That’s my favourite shot in the movie,” says Demme after the tape recorders have been turned off and he and Hathaway have been beckoned into another hotel boardroom. (Probably to talk about Hathaway’s Oscar chances which, to her credit, she seems wholly uninterested in discussing.)

“I can’t even tell you how moving it was for me to have [Corman] there. Thank you so much for noticing him.”

There’s that gracious sensibility again: the words of a man who sounds positively up to his neck in love.