Memo to certain college newspaper editors: David Horowitz soon will give you another chance to prove your devotion to free speech isn't just lip service. Here's hoping you don't blow it the way you did last time.

Yes, Horowitz, a former anti-Vietnam War activist-turned conservative commentator, plans to take another shot at the experiment he tried on college journalism a few months ago. He harbors little hope that this exercise -- submitting a paid ad that will deal with "something about college professors," he told a recent gathering at the Washington-based Eagle Forum -- will fare any better than the previous one. But he's willing to try.

His original effort dealt with the thorny question of whether black Americans deserve to be paid "slave reparations." It was called, provocatively enough, "Ten Reasons Why Reparations Are a Bad Idea for Black People -- And Racist, Too." It argued that blacks in America enjoy the highest standard of living of blacks anywhere in the world and that "trillions of dollars in transfer payments have been made to African-Americans in the form of welfare benefits," thus retiring any "debt" they're owed.

Whatever one thinks of his arguments, Horowitz developed his ad not to debate the reparations question per se but to expose the sad state of free speech on college campuses today. It worked: Of the 73 colleges he submitted the ad to, 41 refused to run it. Of the 28 that did, most editors -- including those at my school, Princeton University -- published editorials denouncing Horowitz's views. (It's still "pending" at the remaining four.)

This, of course, was the purpose of Horowitz's exercise: to demonstrate that while politically correct thought enjoys wide, approving play in college papers, alternative views often can't even pay their way into the paper. You don't have to oppose slave reparations to realize that this violates any conceivable notion of fairness -- let alone any notion of what it means to be part of college life or America itself.

The real world doesn't function like this. In America, the right to argue is among our most sacred privileges. All views get a hearing, or at least should. After all, we go to college not simply to learn the rudiments of some profession -- we could attend trade schools for that -- but to challenge and expand our minds, to confirm our beliefs and perhaps discard them when we find something better.

So why did so many student editors reject the reparations ad?

Jennifer Schaum, executive editor at the University of Virginia's Cavalier Daily, defended her paper's decision to reject it. "We had no desire to profit from publishing an offensive ad designed only to inflame our readers," she said. "Serving our community means striving to serve minority students."

Never mind that Ms. Schaum would not "profit" from the ad either way -- at most schools, most of the student newspaper budget comes from activities fees, and most schools don't link the salaries of its newspaper staff to advertising revenues. So while it would be nice to applaud her for protecting the school from this garish profiteering, one strongly suspects other motives. But what is American journalism coming to when editors strive not to "inflame" readers? Good thing Horace Greeley didn't think like that. Or Katharine Graham.

And how does it "serve minority students" to reject the ad? Perhaps some minority students would like to read the ad for themselves. Afterward, many might see Horowitz as the embodiment of human evil, but some may agree with him. (Don't these papers publish letters to the editor?) Beyond that, how does it make sense in a college environment, of all places, to stifle debate on any subject, especially one as intellectually and emotionally charged as race?

Duke University's newspaper ran Horowitz's ad, despite student complaints that it was "not based on factual evidence." Yet their problem doesn't appear to be with his accuracy -- the facts he presents are easily investigated -- but with his point of view. The students who protested seem afraid to let their fellow students judge his point of view for themselves.

It would be nice this fall if college editors don't let Horowitz play them as easily as he did in the spring. It would be nice if they published his ad and challenged their readers to think and debate. Truth can win in the marketplace of ideas -- but editors should realize that fairness demands a level playing field.

Scott Jeffrey, a sophomore at Princeton University, is an intern at The Heritage Foundation (www.heritage.org ), a Washington-based public policy institute.