To paraphrase the title song, that “Shaft” is one bad … movie.

Isaac Hayes’ theme song from the 1971 original, of which this is either a remake or a sequel (the movie itself seems unsure which), is intact and as cool as ever. And the film even starts out that way.

Samuel L. Jackson — who, it must be stated, would be the butt-kickingest man alive even if he were in a quilting bee — plays John Shaft, nephew of the John Shaft from the original “Shaft.” (Richard Roundtree makes a cameo, reprising his role as Shaft the First.) Shaft the Second is a New York City cop, and he don’t play by the rules, as evidenced by his punching suspects in the face. Sure, the one he hits is Christian Bale as an impossibly evil racist man who killed a black guy, but still, you don’t go fist-whipping your collars, even if they are Christian Bale.

Anyway, Bale’s character, Walter Williams, is rich and gets off scot-free, which makes Shaft hang up his badge. Actually, he hurls it like a Chinese star and imbeds it in the wall behind the judge’s head — the first real sign that this movie has crossed the line from campy ’70s-style fun into true badness.

Because for a while there, you notice the wah-wah guitars on the soundtrack, and the fact that Shaft has more attitude than actual good lines, and the fact that every white person is racist and all the bad guys are like comic book characters … and you kind of sit back and enjoy it. It seems intentionally cheesy, as if trying to re-create the look and feel of the films we loved 30 years ago but are now sort of embarrassed by.

But the novelty of ’70s cheesiness wears off after a while, and the film becomes a run-of-the-mill police drama, culiminating in — yes! — a car chase. Shaft’s lines stop being even ostensibly funny (hearing him tell people to “shut the **** up” is only amusing so many times), and a twisty plot involving a Latino drug pusher (Jeffrey Wright) and Williams is nothing new at all.

Add to that an ending that would seem to encourage vigilantism, and you’ve got yourself a film that, while heavy on attitude, is actually pretty light on personality or even entertainment value.

I doubt anyone other than Jackson could have made “Shaft” even as tolerable as it is. Yet even he is more a state of mind — “cool” — than an actual person. His considerable talents help the terrible screenplay, but they don’t rescue it altogether.

C+ (; R, abundant harsh profanity, sexual dialogue, brief partial nudity, frequent shootings and other violence.)