LAST WEEK, President Bush flew to Cleveland, where he dared to speak the v-word, which is to say "vouchers."

The president long has been a supporter of vouchers. But because the term isn't widely understood and has drawn ridicule, especially from Democrats, Bush long ago dropped the word from his active vocabulary. Even before he took office, Democratic resistance to vouchers led him to edit a voucher proposal out of his education bill, a move that facilitated its passage.

But now the president once again is endorsing vouchers in a public venue. They offer a way of achieving "educational excellence for every child," he said in Cleveland.

Now, there is more the president could do for vouchers and school choice generally, a lot more. Yet it must be said that he already has governed in a way supportive of those ideas.

How? Consider that the authority of a president includes not only the power to recommend legislation but also the power to litigate an agenda. Bush recommended a voucher-less education bill, yes, but he also litigated in behalf of vouchers. He did that in a case from--now you can connect the dots--Cleveland. Indeed, it is the administration's victory in the Cleveland case that now offers the president an auspicious moment to advance the cause of school choice.

In 1995, the condition of education in Cleveland had so deteriorated that the state of Ohio authorized a "scholarship" program under which parents may choose to use checks--i.e., vouchers--from the city to send their children to religious and other private schools, as well as public schools in adjacent districts. With the schools chosen being almost entirely religious ones, Cleveland residents (backed by teachers unions and civil liberties groups) challenged the program as an unconstitutional establishment of religion.

The lower courts agreed with their argument. When the state appealed to the Supreme Court, the Bush administration entered the case the only way it could--since it wasn't one of the parties--as a friend of the court. Zelman vs. Simmons-Harris happened to be the first case the administration joined in that fashion. It didn't have to get into the case. It could have stayed on the sidelines. The decision to enter the case was a deliberate one--just as it would have been for a Democratic administration, though in that case the position taken probably would have been against the program.

In Zelman, the court did what the Bush administration hoped it would, as it set aside the constitutional objection long raised against vouchers and articulated supportive principles. Henceforth, voucher programs will be constitutional so long as they encompass both secular and religious schools and so long as parents receiving the vouchers are free to "exercise genuine choice among options public and private, secular and religious." Significantly, the programs won't be deemed unconstitutional if most parents choose the religious-school option.

In Cleveland, Bush said it now was his job "to take this court decision and encourage others to make the same decision at the local level." But here the president needs to sharpen his arguments. As Justice Clarence Thomas pointed out in a remarkable concurring opinion, vouchers promise help especially for poor, inner-city children forced to attend failing public schools. That is precisely the situation the Cleveland program addresses. But in his Cleveland remarks, Bush failed to make that argument.

Also, Bush usefully could press for religious toleration. The fact is, it will be difficult for more than a handful of "others to make the same decision at the local level" so long as so many states--36 in all--have in their constitutions provisions that flatly deny funding for church-related schools. Those provisions are products of late-19th-century anti-Catholic bigotry and could be used against programs modeled after Cleveland's. A presidential speech could expose those provisions for the hostility toward religion they embody.

Yet the boldest move the president could make for school choice would be to take up the suggestion of Occidental College's Matthew Miller and ask Congress to fund a voucher experiment in three big cities with failing public schools. Under such an experiment, the cities would raise their per-pupil funding by 20 percent to 30 percent. And they would agree to change entirely to a voucher system in which all parents could use the higher per-pupil expenditure at whatever schools--private or public--they might choose.

An experiment along such lines is appealing, since there currently is no conclusive evidence as to the effectiveness of vouchers. Watching several cities operate under a voucher system should provide all the evidence anyone would need.

Terry Eastland is publisher of The Weekly Standard.