He’s back.

The Rev. Al Sharpton, fresh from his recent campaign to help Michael Jackson make the world safe for white blacks everywhere, has undertaken a new crusade. He wants to cut “Barbershop.”

Well, actually, he wants to censor one scene from the hit movie. That scene lampoons several black icons, including Martin Luther King Jr., Rosa Parks and Jesse Jackson.

If you haven’t seen “Barbershop” yet, well … you should. It’s funnier than a Jerry Falwell interview.

The movie chronicles a day in the life of a tonsorial establishment on Chicago’s storied South Side. In the scene in question, Eddie, a crusty old barber, launches a tirade against some black sacred cows. He preaches that O.J. did it and Rodney King deserved it. Other characters start shouting him down, but he won’t be silenced. Martin Luther King was “a ho.”‘ Rosa Parks did nothing but sit her “black a–“‘ down. And as for Jesse Jackson? “Bleep Jackson,” he says.

Except he doesn’t say bleep.

Sharpton supported by Jesse Jackson and a spokeswoman for the 89-year-old Parks has pronounced himself offended. He’s demanding that MGM, the studio that released the movie, issue an apology and excise the scene from the eventual DVD and home video versions.

Not that anyone asked, but I think the Rev has a right to be upset. Still, his response amounts to misplaced overkill.

If you’ve ever been in one, you know the black barbershop is more than a place to get your ears lowered. Back in the day, the barbershop was a meeting room, one of the few places black men had that belonged wholly to them. One of the few where they felt free to drop the masks and debate, raucously and with outrageous political incorrectness, pressing issues of sports, sex and politics.

It’s that freewheeling spirit that the scene in question sought to capture. Unfortunately, the writers miscalculated what they could get away with. They crossed the line. Granted, that line is a subjective one. On the other hand, when you find yourself denigrating a martyred Nobel Prize winner and a frail old woman, you can be reasonably sure you’ve stepped over it.

That trespass has caused Sharpton to focus his ire reflexively and somewhat predictably on the big white company that released the film. But what about the black actors who starred in it, the black-owned production company that helped shape it, and the black test audiences that reportedly laughed themselves breathless after screening it? What’s their responsibility here?

The issue, you see, is not racial, but generational. The civil rights movement ended 34 years ago before most members of the movie’s principal cast were born. They are children of a different time.

More to the point, they are members of a generation raised to be impious and irreverent, a generation for which too far is never far enough. By definition, they will have trouble truly understanding much less embracing the sacrifices made by their elders once upon a time in a world far away.

Add to that the fact that the civil rights movement has been poorly and inconsistently taught, too frequently reduced to caricature and Hallmark sentiment. It becomes an endless loop of M.L. King Jr. repeating “I have a dream” instead of what it was something daring and dangerous.

To understand this is to suspect that, if the writers miscalculated, if the actors crossed a line, maybe it’s because they cannot revere what they only imperfectly understand. Perhaps that scene in “Barbershop” represented an opportunity to help them understand, had the issue been approached less confrontationally and at a lower decibel level.

Instead, Sharpton took it as a chance to cross swords with the white corporate dragon and, perhaps not incidentally, to get his name in the paper. Which is a pity. “Barbershop” is a black movie white audiences have been lining up to see. Top movie in the country the first weeks of its release.

Maybe the Rev needs to be reminded just what it was Rosa and Martin were fighting for.