It’s understandable why Helen Mirren should be starring in “Love Ranch”—it was made by her husband, Taylor Hackford. What’s inexplicable is why Hackford should have chosen to make it in the first place.

To be fair, one can imagine a interesting movie based on the story of Joe and Sally Conforte, the proprietors of the Mustang Ranch, one of Nevada’s first legalized bordellos, whose marriage and business were shaken when Joe bought out the contract of boxer Oscar Bonavena and Sally and the pugilist got involved. But Mark Jacobson’s script avoids any depth and goes for the obvious, on both the professional and the romantic sides. Presumably the aim was to meld dark humor with passionate ardor and high drama. But the tone here is lumpy, crass and overheated.

A major cause of the movie’s abject failure is the performance of Joe Pesci as Charlie Bontempo, as Joe has been rechristened. From the very first he’s just a strident, pugnacious loudmouth who struts around yelling like a refugee from a road company version of one of Scorsese’s mob movies. He quickly grows tiresome. And Sergio Peris-Mencheta, as the over-the-hill boxer Armando Bruza, has some grungy charm but a very limited range. Nor do supporting players like Gina Gershon, Scout Taylor-Compton and Taryn Manning, as three of the brothel’s stable of girls, or suddenly-hot Bryan Cranston, in a small role as a corrupt politician, add much.

That leaves Mirren, and she proves that even in an ill-written part for which she seems completely unsuited, she can triumph. It’s true that Hackford indulges her, but who cares when the result is the only redeeming feature in an otherwise shrill and tedious exercise. Mirren brings some genuine ferocity to a piece that otherwise seems all phony showiness, except for the single fight sequence, which the director stages as though it were “Raging Bull.”

But even Mirren can’t compensate for soap operatic plot turns that involve such things as a steel plate in the boxer’s head that makes any ring action potentially fatal, or a diagnosis of terminal cancer that comes out of thin air. Perhaps such twists have a basis in the historical record, but if so, Jacobson and Hackford don’t present them in a way that enhances their plausibility. And when they stage confrontations between the ranch owners and group of local demonstrators protesting legalized prostitution as immoral, they certainly don’t employ any subtlety.

Hackford, his crew (production designer Bruno Rubeo, art director Mark Duran, set designer Marisa Frantz and decorator Maria Nay, and costume designer Melissa Bruning) and cinematographer Kieran McGuigan do manage to fashion a grubby, dank setting for the story, with the Love Ranch, as the stand-in for the Mustang has been renamed, looking like a authentically seedy joint with a glossy veneer. Their movie, unhappily, fails to make up for its emptiness with even an appearance of quality, though Mirren’s mere presence certainly adds a touch of class.