In 1966, the movie “Django” premiered.  Like the other Spaghetti Westerns, its protagonist was a laconic anti-hero who dealt death to unwashed, unshaven, and unsavory characters; the difference was that “Django” cashed in on the struggling Civil Rights movement in America, revealing a morally bankrupt and racist American West.  Now, in 2012, iconoclastic writer-director Quentin Tarentino, who previously paid revisionist homage to martial arts films with “Kill Bill,” war movies with “Inglorious Basterds,” and film noir with “Pulp Fiction,” has produced his salute to the Spaghetti Western sub-genre with the highly entertaining “Django Unchained.”

In 1858, Dr. King Schultz, a former dentist turned bounty hunter, in an explosive display of violence, buys the slave Django, who can identify three fugitives he is pursuing.  Upon dispatching the outlaws, Schultz only grants Django his freedom, but partners with him in his bounty hunting, and then assists Django in an intricate plot to free Django’s wife, Broomhilda from the despicable slave owner Calvin Candie.

The colorfully-named characters come to life with the expert cast.  Jamie Foxx (“Ray”) is the righteously vengeful Django.  Christoph Waltz (“Inglourious Basterds”) plays the flamboyantly eloquent Dr. Schultz.  Leonardo DiCaprio (“J. Edgar”) portrays the ostentatiously megalomaniac slave owner Candie.  Kerry Washington (“The Details”) is understandably tearful as Broomhilda.  Samuel L. Jackson (“The Avengers”) is physically unrecognizable as the malignant house servant Stephen.  Don Johnson (TV’s “Nash Bridges”) plays Big Daddy, the comically racist plantation owner.  Franco Nero (the original “Django”) makes a cameo as Amerigo Vessepi.  Bruce Dern (“The Cowboys”), Dennis Christopher (“Breaking Away”), Russ Tamblyn (“West Side Story”), Jonah Hill (“Moneyball”), and Robert Carradine (“The Long Riders”) also make brief appearances.

As always with a Quentin Tarentino script, the over-the-top dialogue is sparkling, and the plot is brilliantly sardonic—witty and humorous, sudden and violent, with just the right dash of seriousness to not only honor the original subgenre while poking a little fun at it, but also to convey a not-so-subtle message.  At times reminiscent of Mel Brooks’ “Blazing Saddles,” the script is often profane and irreverent—and always surprising, launching twists to clichés with aplomb.  Mr. Tarentino also makes deft use of Fred Raskin’s expert editing and Robert Richardson’s superlative cinematography.  The opening scene in which Schultz “acquires” Django is just spectacular—brilliantly emphasizing all three of these arts.  Other scenes (the KKK-like raid, the snow-man scene, the dinner/skull scene) also illustrate Mr. Tarentino’s expertise.

But the whole movie begins to unravel and lose momentum about two-thirds of the way through, and what was originally a sly script becomes bitter.  Django doesn’t just play a man pretending to be hateful—he actually becomes as violent and bloodthirsty as those he seeks to kill.  Unlike Schultz, he cannot compartmentalize his moral and his violent acts, and he seems to revel in the revenge he takes as the film devolves into a gory bloodbath.  This is a conscious move by Mr. Tarentino, showing that you cannot separate yourself from your actions (and at the same time justifying that devolution as a “normal” reaction to the actions of others), but it makes Django a less attractive protagonist, one that the audience isn’t rooting for like it was when the movie began.  At the same time, the dialogue degenerates into a slurry of cursing and racial epithets, all the wit-filled lines evaporating like water on a hot skillet, leaving only a bad smell.

I have mixed emotions about “Django Unchained.”  It begins as a witty and surprisingly hopeful film, but descends into a disturbing commentary on human nature.  It well deserves its R rating, with graphic language and violence.