It seems such a wonderful opportunity. Tunica County, Miss., once the poorest county in America, is awash in new money generated by the area's booming casino industry.

The county's school system, once among the poorest and most segregated in the country, is proposing to establish a spanking new state-of-the-art school facility at Robinsonville, in the shadow of the casino hotels along the Mississippi River. So why aren't the black residents of Tunica County grinning all over themselves?

Because, says Rep. Bennie Thompson, the black congressman whose 2nd District constituency includes Tunica, the only effect the new school would have on Tunica's poor black children is to lock them in the inferior and segregated schools they have attended since whites fled the system to avoid racial integration.

The $8 million elementary school would be located hard by a new housing development planned to accommodate Tunica's middle-class influx, drawn to the area by the bustling casinos. Because hardly any county blacks could afford the new housing, few would be in the new school's attendance zone.

Thompson, a Democrat, has asked Attorney General Janet Reno to block the proposal as it now stands, on the ground that it is calculated to circumvent a 1970 desegregation order to which Reno's Justice Department is a party.

He made his argument in a recent letter to Reno, co-signed by two dozen other members of the Congressional Black Caucus.

The effect of the school proposal, the Aug. 3 letter said, would be to provide whites a publicly funded segregated academy. (While Tunica's population is 76 percent black, its public schools are 99 percent black.) Indeed, a housing needs study commissioned in support of the new school includes this passage:

"The cost per child at the private school is considered a problem for a majority of the Anglo American casino employees that presently live outside the county. This is further compounded by the fear of being ostracized by the existing Anglo American residents for enrolling their children in the public school system."

About the only concession to desegregation is a recent offer to save 250 seats for African American children. But that would be accomplished by extending the attendance zone to the point where it overlaps an existing school district.

Black opponents of the proposal -- mostly poor and ill-educated -- have taken on powerful interests ranging from the wealthy landowners on whose plantations they once sharecropped to Senate Majority Leader Trent Lott. It should help that they are in the right.

The major justification for allowing casinos into the state in the first place was the undreamed-of revenues they would bring, particularly to poverty-stricken places such as Tunica, whose most famous landmark used to be Sugar Ditch, the notorious open sewer in the black section of the town of Tunica. The casinos would be the means by which Tunica County educated its children, improved its dreadful housing and put its residents to work.

And in truth, the casinos have created hundreds of decently paid jobs -- though many of the new workers commute the 30-some miles from Memphis or from neighboring Desoto County. Relatively few of the new jobs have gone to black residents, whose unemployment rate stands at 11 percent compared with a white rate of 1.1 percent, according to Thompson's office.

Still, if county and school district officials were of a mind to do it, the money could go a long way toward bringing Tunica County out of the shadows of poverty and racial isolation. They could build the new school not just for the children of the middle-class newcomers but also in a location that would serve the black children who already are there. There is, if officials choose to spend it, enough money to help these poor children overcome much of the legacy of their undereducation.

Tunica, in short, has the opportunity not merely to justify the casinos but to show what can happen when people of goodwill (and adequate funding) decide to combat their racial problems.

The fear here is that Tunica will use its new wealth to teach a different kind of lesson: that if segregationists are persistent enough, clever enough, brazen enough and flush enough, they can win.

This native son of Mississippi was hoping the state would try for a worthier sort of victory.