In a recent confrontation between protesters against the illegal flood of unaccompanied children into the United States and counter-protests by some Hispanic group, one man from the latter group said angrily, "We are as good as you are!"
One of the things that make the history of clashes over race or ethnicity such a history of tragedies around the world is that -- regardless of whatever issue sets off these clashes -- many people see the ultimate stakes as their worth as human beings. On that, there is no room for compromise, but only polarization. That is why playing "the race card" is such an irresponsible and dangerous political game.
The real issue when it comes to immigration is not simply what particular immigration policy America should have, but whether America can have any immigration policy at all.
A country that does not control its own borders does not have any immigration policy. There may be laws on the books, but such laws are meaningless if people from other countries can cross the borders whenever they choose.
One of the reasons why many Americans are reluctant to keep out illegal immigrants -- or even to call them "illegal immigrants," instead of using the mealy-mouthed word "undocumented" -- is that most Hispanics they encounter seem to be decent, hard-working people.
This column has pointed out, more than once, that I have never seen Mexicans standing on a street corner begging, though I have seen both whites and blacks doing so.
But such impressions are no basis for deciding serious issues about immigration and citizenship. When we do not control our own borders, we have no way of knowing how many of those coming across those borders are criminals or even terrorists.
We have no way of knowing how many of those children are carrying what diseases that will spread to our children. And we already know, from studies of American children, that those who are raised without fathers in the home have a high probability of becoming huge, expensive problems for taxpayers in the years ahead, and a mortal danger to others.
A hundred years ago, when there was a huge influx of immigrants from Europe, there were extensive government studies of what those immigrants did in the United States. There were data on how many, from what countries, ended up in jail, diseased or on the dole. There were data on how well their children did in school.
As with most things, some immigrant groups did very well and others did not do nearly as well. But today, even to ask such questions is considered mean-spirited.
Such information as we have today shows that immigrants from some countries have far more education than those from some other countries, and do not end up being supported by the taxpayers nearly as often as immigrants from other countries. But such information is seldom mentioned in discussions of immigrants, as if they were abstract people in an abstract world.
Questions about immigration and citizenship are questions about irreversible decisions that can permanently change the composition of the American population and the very culture of the country.
During the era of epidemics that swept across Europe in centuries past, people fleeing from those epidemics often spread the diseases to the places they fled. Counterproductive and dangerous cultures can be spread to America the same way.
Willful ignorance is not the way to make immigration decisions. Yet the Obama administration is keeping secret even where they are dumping illegal immigrants by the thousands, in communities far from the border states.
Looking before we leap is not racism -- except in the sense that anything the Obama administration doesn't like is subject to being called racist.
Americans who gather to protest the high-handed way this administration has sneaked illegal immigrants into their communities can expect the race card to be played against them. The time is long overdue to stop being intimidated by such cheap -- and dangerous -- political tactics.
Thomas Sowell is a senior fellow at the Hoover Institution, Stanford University.