The depressing news out of Hempstead High School last week - that its academic ranking is in the lowest 5 percent of schools statewide - might send people scurrying for the usual explanations.

Is the result due to the high poverty rate in the district, perhaps? Or maybe the poor showing is because of immigration, leading to too many English language learners in classrooms. Or it could be that the school district is short on money.

But the numbers suggest that none of those explanations is sufficient to justify the ongoing failure, year after year, of Hempstead schools to educate their population.

The data show that three of Long Island's worst-performing districts - Hempstead, Wyandanch and Roosevelt - are teaching roughly the same type of population as three districts performing in the middle statewide: Freeport, Westbury and Bay Shore.

In other words, given the same challenges, some school districts are instructing their kids far better - and for even less cost.

So, one has to ask the question, why is that?

"The answer to me as to why there are differences in those districts is pretty clear-cut, and it has to do with leadership - the school boards and the superintendents," said Roger Tilles, Long Island's representative on the New York State Board of Regents. "The boards of Hempstead and Wyandanch are very dysfunctional. The children are not their first priority of interest. The employment opportunities are the first priority."

In other words, the focus is on hiring friends and relatives, and firing enemies. Wyandanch, in fact, repealed an anti-nepotism policy that, in 2009, state education leaders had praised.

Roosevelt is making some changes in this regard, including bringing in a new superintendent from outside the state. About this district, Tilles and others are hopeful.

But Freeport, Westbury and Bay Shore have been more successful for years. The numbers make the case.

Free and reduced-price lunch, which is a proxy for low-income, averages 73 percent in Hempstead, Wyandanch and Roosevelt, according to New York State Education Department report cards. The average among Freeport, Westbury and Bay Shore is 63 percent. So that's the majority of kids in both cases.

Per-pupil spending in the three struggling districts averages $25,096. In the three mid-performing districts, it is $22,560. On average, the successful districts are spending 11 percent less. That's a meaningful savings in these tight-budget times.

And the graduation rate in Freeport is 74 percent, according to Nassau BOCES, and in Westbury, it's 79 percent. Hempstead's graduation rate is a dismal 38 percent - Long Island's lowest.

One problem in Hempstead is the constant change in direction. In six years, the district has had four superintendents, four business officials, five high school principals, and 18 elementary school principals among eight buildings. There's no continuity.

Hempstead created academies within the high school three years ago to improve student performance; this year the district dissolved them. Last year, it pulled 40 kids out of a BOCES arts and music program two months into the school year. Needless to say, dramatic swings like that are bad for students.

For several years, Tilles has advocated passing a law that would allow the appointment of a special czar in a school district where performance is low and the board can be shown to be dysfunctional - not making decisions in students' best interest. The bill has gone nowhere in the State Senate.

On another front in the battle to rescue failing schools, the State Education Department has told two high schools in Buffalo to allow its students to depart for better districts or BOCES - a move Buffalo is fighting. Long Island school officials are watching this skirmish closely. The lessons learned could soon apply to Hempstead and Wyandanch.