Of course we are a nation of immigrants. But we are also a nation of people who wear shoes.
Does it follow that we should admit anybody who wears shoes?
The immigrants of today are very different in many ways from those who arrived here a hundred years ago. Moreover, the society in which they arrive is different.
The Wall Street Journal column ends by quoting another economist, who said, "Better to build a wall around the welfare state than the country."
But the welfare state is already here - and, far from having a wall built around it, the welfare state is expanding in all directions by leaps and bounds.
We do not have a choice between the welfare state and open borders. Anything we try to do as regards immigration law has to be done in the context of a huge welfare state that is already a major, inescapable fact of life.
Among other facts of life utterly ignored by many advocates of de facto amnesty is that the free international movement of people is different from free international trade in goods.
Buying cars or cameras from other countries is not the same as admitting people from those countries or any other countries.
Unlike inanimate objects, people have cultures, and not all cultures are compatible with the culture in this country that has produced such benefits for the American people for so long.
Not only the United States, but the Western world in general, has been discovering the hard way that admitting people with incompatible cultures is an irreversible decision with incalculable consequences.
If we do not see that after recent terrorist attacks on the streets of Boston and London, when will we see it?
"Comprehensive immigration reform" means doing everything all together in a rush, without time to look before we leap, and basing ourselves on abstract notions about abstract people.
Sowell is a senior fellow at the Hoover Institution, Stanford University, Stanford, CA 94305. His website is www.tsowell.com.