Buoyed by the recent U.S. Supreme Court ruling, President Bush is once again singing the praises of educational vouchers, which give taxpayer funds to families who want to send their children to private schools. Bush declared the ruling, which upheld a Cleveland voucher program, "just as historic" as Brown v. Board of Education, which struck down legally segregated schools.

"The Supreme Court in 1954 declared that our nation cannot have two education systems ... one for African-Americans and one for whites," Bush said. "...Last week, the court declared that our nation will not accept one education system for those who can afford to send their children to a school of their choice and [another] for those who can't."

It was no accident that the president chose to compare the voucher ruling to the Brown case, which was a conerstone of the civil rights movement. Conservatives have been using poor black and Latino children as mascots in their voucher crusade for a decade.

Voucher critics have reason to be wary of the right's sudden interest in schooling poor children of color. The crusade for vouchers actually has its roots in an effort to continue segregation: Back in the 1960s, private white-only schools - so-called "segregation academies" - sprang up across the South in the wake of the Brown decision. By the time of Jimmy Carter's presidency, the parents of seg academy students were campaigning for tax breaks for private school tuition. They formed the early core of what later became the voucher movement.

But let's assume that many conservatives, including Bush, genuinely want to help poor children get a better education. Why have they too turned to vouchers?

To start, the money doesn't add up. Most of the nation's voucher experiments hand parents about $2,000 annually; Cleveland's vouchers are worth $2,250 per year.

Now take a look at private school tuitions. The toniest private schools in the Atlanta region charge $10,000 to $12,000 per year. (No, I'm not talking about colleges.) Parochial schools in the region charge from $5,000 to $10,000 a year. So what private schools are very poor children going to attend?

Even if the children were given full scholarships, there is no evidence their academics would improve. Research from voucher experiments across the country shows little or no improvement in test scores from children who left public schools for private schools.

That should come as no great surprise. The element that matters most in a child's education is the experience at home, not the experience inside the classroom. Common sense says so, and piles of research back it up. It is no accident that public schools in wealthy suburbs show higher test scores than public schools in the ghetto.

Poor children come from homes where parents have little education or sophistication; they are too overwhelmed or intimidated to attend parent-teacher conferences; they tend not to read to their children or to take them to the zoo or to museums. Those children don't get Suzuki violin lessons, infant swim classes or even a Dr. Seuss book.

If Bush wanted to help poor children, he would provide more funds for highly developed day care programs for toddlers and after-school programs for children in the primary grades. He would shore up health care for poor children, since it's hard to learn to read and write when you're wheezing from asthma or you have an undiagnosed hearing or eyesight problem. Bush would make sure that food stamps are available to all eligible parents, since nutrition affects a child's learning, as well.

Those policies wouldn't win the same thunderous applause from voucher supporters on the campaign trail, but they'd do a lot more to help poor kids learn.