The editorial page of the Wall Street Journal has long been an indispensable voice of conservatism. As President Bush said in 2003 in awarding the Medal of Freedom to editorial page editor Robert L. Bartley shortly before his death, he—and by extension his editorial page—has been "a champion of free markets, individual liberty and the values necessary for a free society."

But there is one area in which the editorial page's policy diverges strikingly from conservative orthodoxy, and that is on the matter of immigration. To varying degrees, the paper's editorialists have argued in favor of a more flexible attitude toward immigration. That tendency reaches its apotheosis in the recently-released book by WSJ editorial board member Jason Riley: Let Them In: The Case for Open Borders.

Riley appeared on this weekend's Journal Editorial Report on FNC to discuss his book with host Paul Gigot and make the case that borders should indeed be opened. Riley seemed surprisingly passive in the defense of his controversial proposal, and I personally came away unpersuaded. Here was the exchange.

View video here.

PAUL GIGOT: Nearly 400 suspected illegal immigrants were arrested this week in a raid on a meatpacking plant in Iowa. Federal officials say it was the largest operations of its kind in U.S. history. Wall Street Journal editorial board member Jason Riley is the author of the new book Let Them In: The Case for Open Borders. He joins me now. Jason, I think a lot of Americans will say looking at a raid like this at a plant and finding 400 illegals, why should these people have a right to break the law and come and work in this country?

JASON RILEY: Well I think the real lesson to take away from this is, well there are a couple lessons. Do we want our homeland security resources being put to use this way? Is this the best, most efficient use of them? The case for open borders is a case for moving our immigration policy in a more market-oriented direction. The workers at the plants were coming to this country to work. Why not let them come legally? And therefore our homeland security forces would be able to focus on real threats. Which are not meat packers in Iowa.

GIGOT: You are not saying they weren't with breaking the law.

RILEY: Of course they were breaking the law. But the reason they were breaking the law is because we have a policy in which too many immigrants are chasing too few visas. I believe that the best way to reduce illegal immigration and to prevent illegal workers working in factories is to give people who come here to work more ways to come legally. The best way to to decrease illegal immigration is to provide more legal ways to come here to work. And we know that this is effective because we tried it before. We had a bracero program after World War II to take care of a shortage of farm workers. And when that program was in effect, illegal immigration from Mexico was reduced to a trickle. Now there are all kinds of problems in terms of worker exploitation with this program so Iwouldn't recommend resurrecting it in the exact form; we'd have to tinker with it. But the fundamental principle is sound. If you give people more legal ways to come you get less illegal immigration.

GIGOT: Other objection to your ideas for immigration are the social costs of illegal immigration. They are here. They use our emergency rooms. Health care emergency rooms. Their children get educated in our schools. We have to educate them because of a Supreme Court ruling, Plyler v. Doe. Why should the hard-working American taxpayer have to support the social service costs for people who are here illegally?

RILEY: Well, there are a couple answers to that. One is a lot of people are unaware that immigrants, illegal immigrants, can't receive federal welfare benefits. So that cuts that out right there.

GIGOT: No, but they do go to emergency rooms.

RILEY: They go to emergency rooms and they can get things like Medicaid at the state level and so forth. But you have to keep in mind that immigration benefits both parties. It benefits not only the immigrants themselves but also the people in the recipient country. Immigrants are also consumers. They don't just take. In other words, they buy cars, they buy homes, they get their hair cut.

GIGOT: So economically they're a net plus?

RILEY: Well, they create more economic activity. And creating more economic activity helps our economy grow and in the long run creates even more jobs. So the studies -- and there have been studies done at the state level. Texas has done a study which the controller of Texas found that illegal immigrants were a net plus for the state.

GIGOT: Let me raise another issue which is assimilation, because a lot of people think that you compare this wave of immigrants, Hispanic mostly, to the Italians and the Irish of an earlier era. A lot of critics would say: look those folks did assimilate. The Hispanics in fact in this country are so numerous they can form these enclaves in parts of the country where they do not learn to speak English, where they do not assimilate. What's the evidence that they are assimilating?

RILEY: Well, there's plenty of evidence. We usually measure assimilation in terms of English-language skills, home-ownership rates, climbing out of poverty and so forth. I mean, people look back at the Europeans who came 100 years ago and it's sort of 20/20 hindsight. We sort of romanticize who was coming at the time. There is every indication that immigrants are learning English today and that they are increasing their income and so forth. They are assimilating.

I was particularly struck by Riley's notion that "the best way to reduce illegal immigration and to prevent illegal workers working in factories is to give people who come here to work more ways to come legally." By the same logic, I suppose decriminalizing most larceny would reduce illegal theft. But would that be a good idea?

—Mark Finkelstein is a NewsBusters contributing editor and host of Right Angle. Contact him at mark@gunhill.net.