Was I aware, the young Hispanic wondered, of two studies of illegal immigration -- one by "an obscure professor at Rice University," the other by "a noted professor at the University of Maryland?"

His obvious, if somewhat slanted, reference was to Rice's Donald L. Huddle, who said his research shows Americans losing thousands of jobs to illegal immigrants, and to Maryland's Julian L. Simon, whose unorthodox claim is that the illegals don't take jobs at all but essentially create their own.

The irony is that the question came during the question-and-answer session following a speech, at St. Philip's College here, in which I had urged "a new level of honesty" in our political debate.

It turns out that there was a second irony as well. Even while our exchange was underway, the federal government was revealing a "startling" increase in the number of illegal aliens entering the United States from Mexico. There were 86,200 arrests of illegals along the Mexican border in January of last year; there were 131,500 last month, and "the February pace has not slackened," said Commissioner Alan C. Nelson of the Immigration and Naturalization Service.

"The best deterrent to illegal immigration is to remove the attraction of easy-to-obtain jobs," said Nelson, in calling for employer sanctions against the hiring of undocumented workers.

That is precisely what my questioner, and much of the Hispanic leadership in this country, does not want.

For a while, the argument against employer sanctions was that the illegals were only taking the jobs that Americans didn't want. When the facts showed otherwise, the argument shifted to a claim, not at all baseless, that employers who stood to be fined for hiring illegal Hispanics might simplify their lives by discriminating against all Hispanics, including legal immigrants and native-born Americans with Hispanic traits.

Now, thanks principally to Simon, there is another argument: "Immigrants don't just take jobs; they also purchase goods and services, thereby enlarging the market, while adding to the national productivity, and they also bring their brains and their creativity. Immigration (including unlawful immigration) helps rather than hurts the economy."

That's the position my clever questioner sought to urge on me. I couldn't buy it, for reasons including the one Colorado Gov. Richard D. Lamm and Gary Imhoff offer in their recent book, "The Immigration Time Bomb: The Fragmenting of America":

"At least four elements are necessary for an economy to grow: labor, energy, natural resources, and capital formation. The pace of economic growth is set by the element in lowest supply. If an economy has plentiful resources, energy and capital, but has few workers, then increasing the number of laborers will make that economy grow. But in an economy like ours, which is limited by the energy, recources and capital available to it, and in which workers are in oversupply and many are unemployed, adding workers will simply lengthen the lines of the unemployed."

Indeed, I find it difficult to believe that anybody interested in relieving unemployment among Americans, particularly American minorities, can believe that the influx of illegals suggested by 131,000 arrests in a single month (the conventional wisdom is that most unlawful immigrants escape detection) does no harm to the job prospects of America's own jobless.

Surely not all of the employers who hire these illegals would go out of business if they were required to hire only Americans or documented aliens. Nor am I convinced that the illegals take only the low-paid jobs that Americans don't want. As San Antonio, with its depressed wage structure, knows very well, it is the availability of illegals willing to work at substandard wages that turns pretty good jobs into low-paid ones.

The distinction crying to be made is between the contributions of immigrants to America during the whole of its history and the problem of illegal immigration.

There are legitimate arguments to be made over employer sanctions, amnesty and other ways of dealing with the problem.

But, Julian Simon and the young man at St. Philip's notwithstanding, honesty demands that we at least acknowledge that there is a problem.